Name: mass production of entomopathogenic fungi, metarhizium robertsii and metarhizium pinghaense, for commercial application against insect pests
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Description: Watch this Scientific Journal Video about Mass Production of Entomopathogenic Fungi, Metarhizium robertsii and Metarhizium pinghaense, for Commercial Application Against Insect Pests at JoVE.com

The authors would like to thank Hort Pome, Hort Stone, and the Technology and Human Resources for Industry Programme (THRIP: TP14062571871) for funding the project.
ORCID: 
Letodi L. Mathulwe http://orcid.org/0000-0002-5118-3578
Antoinette P. Malan http://orcid.org/0000-0002-9257-0312
Nomakholwa F. Stokwe http://orcid.org/0000-0003-2869-5652

1. Source of fungal strains
<ol>
	<li>Use South African isolated fungal strains of both M. pinghaense 5 HEID (GenBank Accession number: MT367414/MT895630) and M. robertsii 6EIKEN (MT378171/MT380849), collected from apple orchards in the Western Cape province, South Africa.</li>
	<li>Grow cultures of each EPF isolate on 60 g of Sabouraud dextrose agar medium, supplemented with 1 g of yeast extract (SDAY) and 10 &#181;L of Streptomycin. 
	NOTE: Incubate EPF cultures at a c...

<ol>
	<li>Shah, P. A., Pell, J. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Entomopathogenic+fungi+as+biological+control+agents.">Entomopathogenic fungi as biological control agents.</a> Applied Microbiology and Biotechnology. 61 (5), 413-423 (2003).</li><li>Mathulwe, L. L., Malan, A. P., Stokwe, N. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+of+the+biology+and+control+of+the+obscure+mealybug,+Pseudococcus+viburni+(Hemiptera:+Pseudococcidae),+with+special+reference+to+biological+control+using+entomopathogenic+fungi+and+nematodes.">A review of the biology and control of the obscure mealybug, Pseudococcus viburni (Hemiptera: Pseudococcidae), with special reference to biological control using entomopathogenic fungi and nematodes.</a> African Entomology. 29 (1), 1-16 (2020).</li><li>Ibrahim, L., Laham, L., Touma, A., Ibrahim, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mass+production,+yield,+quality,+formulation+and+efficacy+of+entomopathogenic+Metarhizium+anisopliae+conidia.">Mass production, yield, quality, formulation and efficacy of entomopathogenic Metarhizium anisopliae conidia.</a> Current Journal of Applied Science and Technology. 9 (5), 427-440 (2015).</li><li>Banu, J. G., Rajalakshmi, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Standardisation+of+media+for+mass+multiplication+of+entomopathogenic+fungi.">Standardisation of media for mass multiplication of entomopathogenic fungi.</a> Indian Journal of Plant Protection. 42 (1), 91-93 (2014).</li><li>Roberts, D. W., Humber, R. A., Cole, G. T., Kendrick, W. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Entomogenous+fungi.">Entomogenous fungi.</a> Biology of Conidial Fungi. , 201-236 (1981).</li><li>Feng, M. G., Poprawski, T. J., Khachatourians, G. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Production,+formulation+and+application+of+the+entomopathogenic+fungus+Beauveria+bassiana+for+insect+control.+Current+status.">Production, formulation and application of the entomopathogenic fungus Beauveria bassiana for insect control. Current status.</a> Biocontrol Science and Technology. 4 (1), 3-34 (1994).</li><li>Karanja, L. W., Phiri, N. A., Oduor, G. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+different+solid+substrates+on+mass+production+of+Beauveria+bassiana+and+Metarhizium+anisopliae+entomopathogens.">Effect of different solid substrates on mass production of Beauveria bassiana and Metarhizium anisopliae entomopathogens.</a> The Proceedings of the12th KARI Biennial Scientific Conference. , 8-12 (2010).</li><li>Prasad, C. S., Pal, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mass+production+and+economics+of+entomopathogenic+fungus,+Beauveria+bassiana,+Metarhizium+anisopliae+and+Verticillium+lecanii+on+agricultural+and+industrial+waste.">Mass production and economics of entomopathogenic fungus, Beauveria bassiana, Metarhizium anisopliae and Verticillium lecanii on agricultural and industrial waste.</a> Scholars Journal of Agriculture and Veterinary Sciences. 1 (1), 28-32 (2014).</li><li>Ehlers, R. U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mass+production+of+entomopathogenic+nematodes+for+plant+protection.">Mass production of entomopathogenic nematodes for plant protection.</a> Applied Microbiology and Biotechnology. 56 (5), 623-633 (2001).</li><li>Pham, T. A., Kim, J. J., Kim, S. G., Kim, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Production+of+blastospore+of+entomopathogenic+Beauveria+bassiana+in+a+submerged+batch+culture.">Production of blastospore of entomopathogenic Beauveria bassiana in a submerged batch culture.</a> Mycobiology. 37 (3), 218-224 (2009).</li><li>Bhadauria, B. P., Puri, S., Singh, P. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mass+production+of+entomopathogenic+fungi+using+agricultural+products.">Mass production of entomopathogenic fungi using agricultural products.</a> The Bioscan. 7 (2), 229-232 (2012).</li><li>Latifian, M., Rad, B., Amani, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mass+production+of+entomopathogenic+fungi+Metarhizium+anisopliae+by+using+agricultural+products+based+on+liquid-solid+diphasic+method+for+date+palm+pest+control.">Mass production of entomopathogenic fungi Metarhizium anisopliae by using agricultural products based on liquid-solid diphasic method for date palm pest control.</a> International Journal of Farming and Allied Sciences. 3 (4), 368-372 (2014).</li><li>Agale, S. V., Gopalakrishnan, S., Ambhure, K. G., Chandravanshi, H., Gupta, R., Wani, S. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mass+production+of+entomopathogenic+fungi+(Metarhizium+anisopliae)+using+different+grains+as+a+substrate.">Mass production of entomopathogenic fungi (Metarhizium anisopliae) using different grains as a substrate.</a> International Journal of Current Microbiology and Applied Sciences. 7 (1), 2227-2232 (2018).</li><li>Jackson, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimizing+nutritional+conditions+for+the+liquid+culture+production+of+effective+fungal+biological+control+agents.">Optimizing nutritional conditions for the liquid culture production of effective fungal biological control agents.</a> Journal of Industrial Microbiology and Biotechnology. 19 (3), 180-187 (1997).</li><li>Deshpande, M. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mycopesticides+production+by+fermentation.+Potential+and+challenges.">Mycopesticides production by fermentation. Potential and challenges.</a> Critical Reviews in Microbiology. 25 (3), 229-243 (1999).</li><li>Sahayaraj, K., Namasivayam, S. K. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mass+production+of+entomopathogenic+fungi+using+agricultural+products+and+by+products.">Mass production of entomopathogenic fungi using agricultural products and by products.</a> African Journal of Biotechnology. 7 (12), 1907-1910 (2008).</li><li>Feng, K. C., Liu, L. B., Tzeng, Y. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Verticillium+lecanii+spore+production+in+solid-state+and+liquid-state+fermentations.">Verticillium lecanii spore production in solid-state and liquid-state fermentations.</a> Bioprocess Engineering. 23 (1), 25-29 (2000).</li><li>Jaronski, S. T., Jackson, M. A., Lacey, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mass+production+of+entomopathogenic+Hypocreales.">Mass production of entomopathogenic Hypocreales.</a> Manual of Techniques in Invertebrate Pathology 2nd edition. , 255-284 (2012).</li><li>Vega, F. E., Jackson, M. A., Mercandier, G., Poprawski, T. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+impact+of+nutrition+on+spore+yields+for+various+fungal+entomopathogens+in+liquid+culture.">The impact of nutrition on spore yields for various fungal entomopathogens in liquid culture.</a> World Journal of Microbiology and Biotechnology. 19 (4), 363-368 (2003).</li><li>El Damir, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+growing+media+and+water+volume+on+conidial+production+of+Beauveria+bassiana+and+Metarhizium+anisopliae.">Effect of growing media and water volume on conidial production of Beauveria bassiana and Metarhizium anisopliae.</a> Journal of Biological Sciences. 6 (2), 269-274 (2006).</li><li>Pandey, A. K., Kanaujia, K. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+different+grains+as+solid+substrates+on+sporulation,+viability+and+pathogenicity+of+Metarhizium+anisopliae+(Metschnikoff)+Sorokin.">Effect of different grains as solid substrates on sporulation, viability and pathogenicity of Metarhizium anisopliae (Metschnikoff) Sorokin.</a> Journal of Biological Control. 22 (2), 369-374 (2008).</li><li>Kassa, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Whey+for+mass+production+of+Beauveria+bassiana+and+Metarhizium+anisopliae.">Whey for mass production of Beauveria bassiana and Metarhizium anisopliae.</a> Mycological Research. 112 (5), 583-591 (2008).</li><li>Sharma, S., Gupta, R. B. L., Yadavam, C. P. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selection+of+a+suitable+medium+for+mass+multiplication+of+entomofungal+pathogens.">Selection of a suitable medium for mass multiplication of entomofungal pathogens.</a> Indian Journal of Entomology. 64 (3), 254-261 (2002).</li><li>Bich, G. A., Castrillo, M. L., Villalba, L. L., Zapata, P. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+rice+by-products,+incubation+time,+and+photoperiod+for+solid+state+mass+multiplication+of+the+biocontrol+agents+Beauveria+bassiana+and+Metarhizium+anisopliae.">Evaluation of rice by-products, incubation time, and photoperiod for solid state mass multiplication of the biocontrol agents Beauveria bassiana and Metarhizium anisopliae.</a> Agronomy Research. 16 (5), 1921-1930 (2018).</li><li>Price, R. E., M&#252;ller, E. J., Brown, H. D., D'Uamba, P., Jone, A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+first+trial+of+a+Metarhizium+anisopliae+var.+acridum+mycoinsecticide+for+the+control+of+the+red+locust+in+a+recognised+outbreak+area.">The first trial of a Metarhizium anisopliae var. acridum mycoinsecticide for the control of the red locust in a recognised outbreak area.</a> International Journal of Tropical Insect Science. 19 (4), 323-331 (1999).</li><li>Hatting, J. L., Moore, S. D., Malan, A. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microbial+control+of+phytophagous+invertebrate+pests+in+South+Africa.+Current+status+and+future+prospects.">Microbial control of phytophagous invertebrate pests in South Africa. Current status and future prospects.</a> Journal of Invertebrate Pathology. 165, 54-66 (2019).</li><li>Mathulwe, L. L., Malan, A. P., Stokwe, N. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laboratory+screening+of+entomopathogenic+fungi+and+nematodes+for+pathogenicity+against+the+obscure+mealybug,+Pseudococcus+viburni+(Hemiptera:+Pseudococcidae).">Laboratory screening of entomopathogenic fungi and nematodes for pathogenicity against the obscure mealybug, Pseudococcus viburni (Hemiptera: Pseudococcidae).</a> Biocontrol Science and Technology. , (2021).</li><li>Inglis, G. D., Enkerli, J., Goettel, M. 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The successful integration of microbial agents for the biological control of important agricultural insect pests in an agroecosystem depends on both success and ease of mass production of the entomopathogens as the first step under laboratory conditions. The mass production of EPF is important for the large-scale application and availability of EPF products for IPM programs using biological control9,10,11,<sup class="...

Entomopathogenic fungi (EPF) have gained importance as crop protection agents in the biological control of important agricultural insect pests1,2. The entomopathogens, which occur naturally in soil, cause epizootics in the populations of various pest species3. The species of EPF are host-specific and pose relatively few risks in terms of attacking nontarget species, and they are nontoxic to the environment4. EPF have a unique mechanism for invading their host, as well as for propagating and persisting in their immediate environment1. They attack the host mainly through asexual spores that attach to and penetrate the host cuticle to invade and proliferate in the host hemocoel. The host eventually dies due to depletion of the hemolymph nutrients or as a result of the toxemia caused by the toxic metabolites released by the fungus. Following death, under ideal environmental conditions, the fungus emerges on the outer surface (overt mycosis) of the host cadaver5,6.
Growing concerns regarding the negative effects of chemical residues on human health, environmental pollution, and the development of pest resistance have led to the global drive to reduce inputs of chemical-based insecticides and to find alternative, novel, and sustainable strategies for crop protection and pest control6,7,8. This has provided opportunities to develop microbial-based insecticides for use in Integrated Pest Management (IPM) programs, which are more ecologically favorable strategies than conventional chemical control3,8.
To develop a successful microbial control agent for an agricultural pest, a suitable organism must first be isolated, characterized, identified and its pathogenicity for the&#160;target pest confirmed. However, an easy, cost-effective method for large-scale production of the microbial agent is required to produce a viable product for use in biological control programmes9,10,11,12,13. Mass production of substantial quantities of good-quality entomopathogens depends on the microbial strain, the environment, the target pest, the formulation, the market, the application strategy, and the desired end product14,15,16. EPF can be mass-produced using liquid substrate fermentation to produce blastospores or the solid substrate fermentation process to produce aerial conidia6,17,18. However, the mass production and formulation process of entomopathogens directly influences the virulence, the cost, the shelf life, and the field efficacy of the final product. For successful use in IPM, the production process of the entomopathogens must be easy to run, require minimal labor, produce a high-yield concentration of virulent, viable, and persistent propagules, and be low in cost4,13,14,16.
Understanding the nutritional requirements of entomopathogens is important for mass cultivation with all culturing methods4,12. The nutritional components of the production medium have a significant impact on the attributes of the resulting propagules, including biocontrol efficacy, yield, desiccation tolerance, and persistence8,19,20,21. The optimization of production procedures is designed to address such factors22. For EPF, the main requirements for good growth, sporulation, and mass production of fungal conidia are adequate moisture, optimum growth temperature, pH, gas exchange of CO2 and O2, and nutrition, including good phosphorous, carbohydrate, carbon, and nitrogen sources18.
Jaronski and Jackson18 describe the solid substrate fermentation method as the most efficient and the closest approximation method to the natural process for EPF production relative to the liquid substrate fermentation method because, under natural conditions, the fungal conidium is borne on solid erect structures, like the surface of insect cadavers. Agricultural products and by-products containing starch are mostly used for the mass production of hypocrealean fungi, as the fungi readily decompose starch through secretion of highly concentrated hydrolytic enzymes from their hyphal tips, to penetrate the solid substance, and to access the nutrients present in the substance11,17,18,23. The grain products also provide the requirements for healthy biomass production because, when they are hydrated and sterilized, the substrates can absorb further nutrients from any liquid medium16,18,24.
Previously, several studies attempted to mass culture EPF species like Beauveria bassiana (Bals.) Vuil., Cordyceps fumosorosea (Wize) Kelper B. Shrestha &#38; Spatafora, Verticillium lecanii (Zimm.) Viegas and some of the Metarhizium anisopliae (Metschn.) Sorokin species complex isolates on various substrates16,23,24. Such mass-produced and commercially developed isolates include Green Muscle&#174; (strain IMI 330189), developed from M. anisopliae var Metarhizium acridum (Driver &#38; Milner) J.F. Bisch, Rehner &#38; Humber, Metarhizium 69 (Meta 69 strain ICIPE69), and Real Metarhizium 69 (L9281), developed from M. anisopliae, and Broadband&#174; (strain PPRI 5339) and Eco-Bb&#174;, developed from B. bassiana25,26. However, limited attempts have been made to mass culture Metarhizium robertsii J.F. Bisch., S.A. Rehner &#38; Humber and Metarhizium pinghaense Chen &#38; Guo. These two isolates were selected in a previous study as the most effective for the control of the mealybug, Pseudococcus viburni Signoret (Hemiptera: Pseudococcidae)27. Therefore, the current study aimed to formulate and mass-produce a sufficient number of resilient infective propagules of the local isolates of M. robertsii and M. pinghaense for commercial application against insect pests. The solid substrate fermentation method was used to mass-produce the fungal conidia for both EPF isolates. Two EPF inoculation methods, using conidial suspensions and the liquid fungal culture of blastospores, were used to inoculate the solid substrates.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>0.05% Tween 20</td>
			<td>Lasec</td>
			<td></td>
			<td>Added to conidial suspensions to allow fungal spores to mix with water</td>
		</tr>
		<tr>
			<td>20 mL McCartney bottles</td>
			<td>Lasec</td>
			<td></td>
			<td>Used to make conidial suspensions</td>
		</tr>
		<tr>
			<td>Aluminium foil</td>
			<td></td>
			<td></td>
			<td>Used as a cover of the cotton wool plugs on 250-mL flask</td>
		</tr>
		<tr>
			<td>Autoclave</td>
			<td></td>
			<td></td>
			<td>Used to sterilize materials and ingredients used for the conidia production process</td>
		</tr>
		<tr>
			<td>Autoclave bags</td>
			<td>Lasec</td>
			<td></td>
			<td>Fermentation bags or solid substrate containers</td>
		</tr>
		<tr>
			<td>Autoclave tape</td>
			<td>Lasec</td>
			<td></td>
			<td>To secure PVC pipes on the fermentation bags</td>
		</tr>
		<tr>
			<td>Brown Kraft paper bags</td>
			<td></td>
			<td></td>
			<td>Used to dry conidia cultures on agricultural grains</td>
		</tr>
		<tr>
			<td>Bunsen burnner</td>
			<td>Labnet (Labnet International, Inc.)</td>
			<td></td>
			<td>Used to flame equipment (surgical blades,inoculating loops and rims of flasks)</td>
		</tr>
		<tr>
			<td>Clear edge test sieve</td>
			<td></td>
			<td></td>
			<td>Used to separate fungal conidia from agricultural grain substrates</td>
		</tr>
		<tr>
			<td>Corn steep liquor</td>
			<td>SIGMA</td>
			<td>66071-94-1</td>
			<td>Ingredient of the blastospore liquid medium</td>
		</tr>
		<tr>
			<td>Cotton Wool</td>
			<td>Lasec</td>
			<td></td>
			<td>Used as plug of the neck for fermentation bags</td>
		</tr>
		<tr>
			<td>Duran laboratory bottles</td>
			<td>Neolab</td>
			<td></td>
			<td>Used to autoclave SDA medium and distilled water</td>
		</tr>
		<tr>
			<td>Electrical tape</td>
			<td></td>
			<td></td>
			<td>Used to tape and seal the sieve joints to prevent the escape of conidial dust</td>
		</tr>
		<tr>
			<td>ENDECOTTS test sieve</td>
			<td></td>
			<td></td>
			<td>Used to separate fungal conidia from agricultural grain substrates</td>
		</tr>
		<tr>
			<td>Erlenmeyer Flasks, Narrow neck,250-mL flask</td>
			<td>Lasec</td>
			<td></td>
			<td>Carrier of the blastospore liquid medium</td>
		</tr>
		<tr>
			<td>Ethanol (99%)</td>
			<td>Lasec</td>
			<td></td>
			<td>Used to sterilize surgical blades and inoculating loops</td>
		</tr>
		<tr>
			<td>Flaked barley</td>
			<td>Health Connection Wholefoods</td>
			<td></td>
			<td>Agricultural grain used as a solid substrate growth medium for conidia of both M. pinghaense and M. robertsii</td>
		</tr>
		<tr>
			<td>Flaked oats</td>
			<td>Tiger brands</td>
			<td></td>
			<td>Agricultural grain used as a solid substrate growth medium for conidia of both M. pinghaense and M. robertsii</td>
		</tr>
		<tr>
			<td>Glucose</td>
			<td>Merck</td>
			<td></td>
			<td>Ingredient of the blastospore liquid medium</td>
		</tr>
		<tr>
			<td>Growth Chamber/ incubators</td>
			<td></td>
			<td></td>
			<td>For growing fungal conidia culture</td>
		</tr>
		<tr>
			<td>Haemocytometer</td>
			<td></td>
			<td></td>
			<td>Used to determine conidial concentrations</td>
		</tr>
		<tr>
			<td>Inoculating loops</td>
			<td>Lasec</td>
			<td></td>
			<td>For harvesting spores to innoculate liquid medium for blastospores growth</td>
		</tr>
		<tr>
			<td>Kitchen rolling pin</td>
			<td></td>
			<td></td>
			<td>Used to manipulate the solid grain substrate bed</td>
		</tr>
		<tr>
			<td>Laminar flow Cabinet</td>
			<td>ESCO Laminar Flow Cabinet</td>
			<td></td>
			<td>Provide as sterile environment during substrate inoculation</td>
		</tr>
		<tr>
			<td>Metarhizium pinghaense conidia</td>
			<td>Stellenbosch University</td>
			<td>5HEID</td>
			<td>Cultures used to mass culture conidia of Metarhizium pinghaense</td>
		</tr>
		<tr>
			<td>Metarhizium robertsii conidia</td>
			<td>Stellenbosch University</td>
			<td>6EIKEN</td>
			<td>Cultures used to mass culture conidia of Metarhizium robertsii</td>
		</tr>
		<tr>
			<td>Microscope</td>
			<td>ZEIZZ (Scope. A1)</td>
			<td></td>
			<td>Used to determine conidial concentrations and conidial viability</td>
		</tr>
		<tr>
			<td>Orbital shaker</td>
			<td>IncoShake- LABOTEC</td>
			<td></td>
			<td>Used for the blastospore production process</td>
		</tr>
		<tr>
			<td>Parboiled rice</td>
			<td>Spekko</td>
			<td></td>
			<td>Agricultural grain used as a solid substrate growth medium for conidia of both M. pinghaense and M. robertsii</td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin</td>
			<td>SIGMA</td>
			<td></td>
			<td>Added to the SDA medium to prevent bacterial contamination</td>
		</tr>
		<tr>
			<td>Petri-dishes</td>
			<td>Lasec</td>
			<td></td>
			<td>Containers for the SDA medium</td>
		</tr>
		<tr>
			<td>Pipettes and pipette tips</td>
			<td>Labnet (BioPette PLUS)</td>
			<td></td>
			<td>Used to measure liquids ingredients</td>
		</tr>
		<tr>
			<td>Polyvinylchloride Marley waste pipe</td>
			<td></td>
			<td></td>
			<td>Used to create a neck for the fermentation bag</td>
		</tr>
		<tr>
			<td>Potassium phosphate dibasic (K2HPO4)</td>
			<td>SIGMA-ALDRICH</td>
			<td></td>
			<td>Ingredient of the blastospore liquid medium</td>
		</tr>
		<tr>
			<td>Rubber band</td>
			<td></td>
			<td></td>
			<td>Used to secure the secure the surgical paper over the fermentation bag PVC pipe necks</td>
		</tr>
		<tr>
			<td>Sabaroud dextrose agar (SDA)</td>
			<td>NEOGEN Culture Media</td>
			<td></td>
			<td>Medium used to culture spores of both Metarhizium pinghaense and Metarhizium robertsii</td>
		</tr>
		<tr>
			<td>Sterile distilled water</td>
			<td></td>
			<td></td>
			<td>To hydrate agricultural grains, to make conidial suspensions</td>
		</tr>
		<tr>
			<td>Sticky pad</td>
			<td></td>
			<td></td>
			<td>Used to secure the seives on the vibratory shaker</td>
		</tr>
		<tr>
			<td>Surgical blade</td>
			<td>Lasec</td>
			<td></td>
			<td>Used to scrape off spores from fungal cultures</td>
		</tr>
		<tr>
			<td>Surgical paper</td>
			<td>Lasec</td>
			<td></td>
			<td>Used to cover the PVC necks and cotton wool plugs of the fermentation bag</td>
		</tr>
		<tr>
			<td>Vibratory shaker</td>
			<td></td>
			<td></td>
			<td>Used to shake conidia off the agricultural grain substrates</td>
		</tr>
		<tr>
			<td>Vortex mixer</td>
			<td>Labnet (Labnet International, Inc.)</td>
			<td></td>
			<td>Used to mix conidial suspensions in Mc Cartney bottles</td>
		</tr>
		<tr>
			<td>Yeast extract</td>
			<td>Biolab</td>
			<td></td>
			<td>Added to the SDA medium to improve spore germination and growth</td>
		</tr>
		<tr>
			<td>Zipper-lock bags</td>
			<td>GLAD</td>
			<td></td>
			<td>Used to to store harvested fungal conidia</td>
		</tr>
	</tbody>
</table>

mass production of entomopathogenic fungi, metarhizium robertsii and metarhizium pinghaense, for commercial application against insect pests

Entomopathogenic fungi of the Metarhizium anisopliae species complex have gained importance as the biological control agents of agricultural insect pests. The increase in pest resistance to chemical insecticides, the growing concerns regarding the negative effects of insecticides on human health, and the environmental pollution from pesticides have led to a global drive to find novel sustainable strategies for crop protection and pest control. Previously, attempts to mass culture such entomopathogenic fungi (EPF) species as Beauveria bassiana have been conducted. However, only limited attempts have been conducted to mass culture Metarhizium robertsii and M. pinghaense for use against insect pests. This study aimed to mass-produce a sufficient number of resilient infective propagules of South African isolates of M. robertsii and M. pinghaense for commercial application. Three agricultural grain products, flaked oats, flaked barley, and rice, were used as the EPF solid fermentation substrates. Two inoculation methods, conidial suspensions and the liquid fungal culture of blastospores were used to inoculate the solid substrates. Inoculation using conidial suspensions was observed to be relatively less effective, as increased levels of contamination were observed on the solid substrates relative to when using the blastospore inoculation method. Flaked oats were found not to be a suitable growth substrate for both M. robertsii and M. pinghaense, as no dry conidia were harvested from the substrate. Flaked barley was found to favor the production of M. robertsii conidia over that of M. pinghaense, and an average of 1.83 g &plusmn; 1.47 g of dry M. robertsii conidia and zero grams of M. pinghaense conidia was harvested from the substrate. Rice grains were found to favor the conidial mass production of both M. pinghaense and M. robertsii isolates, with an average of 8.2 g &plusmn; 4.38 g and 6 g &plusmn; 2 g harvested from the substrate, respectively.

A decline in the content mass of the cultures on rice for both the M. pinghaense and the M. robertsii was observed over time during the drying stage of the fungal cultures, with no, or little, change being observed in the mass once the cultures were dry (Figure 5). The harvested dry fungal conidia powder of both the M. pinghaense and the M. robertsii is shown in Figure 6.
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Watch this Scientific Journal Video about Mass Production of Entomopathogenic Fungi, Metarhizium robertsii and Metarhizium pinghaense, for Commercial Application Against Insect Pests at JoVE.com

Mass Production of Entomopathogenic Fungi, Metarhizium robertsii and Metarhizium pinghaense, for Commercial Application Against Insect Pests

Entomopathogenic fungi have gained importance as the biological control agents of agricultural insect pests. In this study, the mass production of a sufficient number of resilient infective propagules of South African isolates of both Metarhizium robertsii and M. pinghaense for commercial application against insect pests was successfully conducted using agricultural grain products.

Mass Production of Entomopathogenic Fungi, Metarhizium robertsii and Metarhizium pinghaense, for Commercial Application Against Insect Pests

Entomopathogenic fungi of the Metarhizium anisopliae species complex have gained importance as the biological control agents of agricultural insect pests. ...

This method provides new information on how to mass produce infective conidia of entomopathogenic fungi to control important insect pests in commercial agro-ecosystems, given the current situation where most insecticides are phased out due to concerns of their toxic effect on the environment and human health. The technique describes the method used to ensure the optimum yield of EPF conidia during mass production. The method is helpful for integrated pest management and biological control by providing insight into the effectiveness of mass produced conidia for large-scale management of damaging insecticide resistance insect pests in the agro-ecosystems.This procedure was developed and demonstrated by Dr.Letodi Luki Mathulwe, Dr.Nomakholwa Faith Stokwe, and Professor Antoinette Paula Malan. Heat one liter distilled water and switch off the heat before reaching the boiling point. Now, add 30 grams of glucose, four grams of potassium phosphate dibasic, 20 grams of yeast extract, 15 milliliters of corn steep liquor, and bring the contents to a gentle boil for two to three minutes.Pour a total of 100 milliliters of the medium into nine different 250-milliliter flasks. Place a cotton wool plug on each flask and cover the cotton wool with aluminum foil as a stopper. Autoclave the medium in the flasks for 55 minutes at 121 degrees Celsius.Later, allow the medium in the flasks to cool and add 10 milligrams per milliliter of streptomycin to the medium in each flask. Collect two to three bacterial loops of fungal conidia from two-to three-week-old fungal culture plates for both the EPF isolates. Transfer the fungal conidia to each 100 milliliters of liquid media in the 250 milliliter flasks under sterile conditions and seal the flasks.Incubate the liquid culture flasks at approximately 25 degrees Celsius on an orbital shaker at 140 RPM for three days and cease the incubation once the cultures show signs of high turbidity with fungal blastospore growth. To detect any possible bacterial contamination from the cultures, draw a 100-microliters sample from each liquid culture flask after 24 hours of incubation and plate on three SDA plates per isolate. Incubate the plates for 48 hours at a controlled temperature of plus or minus 25 degrees Celsius.Use a small polyvinyl chloride waste pipe to create a neck for the fermentation bag at the open end of the autoclave bag and use autoclave tape to secure the pipe. Close the pipe with a sterile cotton wool plug to allow sufficient gas exchange during fermentation. Use parboiled long grain white rice as a solid substrate medium for the blastospores of both Metarhizium pinghaense and Metarhizium robertsii.For each fermentation bag, add one kilogram of rice and 300 milliliters of sterile distilled water. Gently mix the contents of the fermentation bags. Place them in outer autoclave bags in an upright position and autoclave at 121 degrees Celsius for 55 minutes.Following the autoclaving, allow the substrates to cool down for about 45 minutes under sterile conditions. Remove the closure of each of the liquid culture flasks of both Metarhizium pinghaense and Metarhizium robertsii under a laminar flow and flame the rim of each flask for 10 seconds. Pour 100 milliliters of liquid cultures into the fermentation bags by removing the cotton wool plugs from their necks.Place the cotton plugs back on and cover the top of the bag's neck with surgical paper secured with a rubber band. Twist the top part of the bag and mix the bag's contents by shaking and manipulating the substrate by massage. Incubate the bags at about 25 degrees Celsius by flattening the substrate in the bags to prevent the formation of thick beds.Two to three days after inoculation and incubation, when visible mycelial growth and the binding of the substrate by the fungus had occurred, break the substrate in the fermentation bags by massaging the bags'contents. Following fermentation, transfer the sporulated cultures into 26-to 30-kilogram brown paper bags and dry the fungal cultures for 10 to 12 days before their use in trials. To improve the tensile strength of the paper bags, horizontally cut off 1/3 of the top part of the bag and line the bottom of the bag.Gently crumble the substrate in each fermentation bag. Cut off the corner of each bag and slowly transfer the whole culture to the paper bags through the space left by the cut off corner. Label each paper bag, fold over the top end of each bag twice, and close with staples to create a triangular tent structure.Place the bags on wire drying racks to allow proper, even drying at a controlled temperature of about 25 degrees Celsius and low humidity of 30 to 40%Harvest fungal conidia from the cultures using three nested sieves mounted on a collection pan. Slowly load the dry culture sample on the ETS mesh number 35 and sieve. Place a lid on the sieve to prevent the release of fungal conidia into the air.Add 10 to 12 glass marbles to the sieves to assist the passage of the fungal conidia through the mesh screens and avoid the retention of the conidia in the sieve, which can result in reduced spore recovery. Tape and seal the sieve joints using electrical tape. Place the sieves on a vibratory shaker fitted with a sticky pad to secure the collection pan and sieves for 20 to 25 minutes at a motion of 560 to 640 vibrations per minute.Remove the test sieves from the collection pan, collect conidia, and store the collected conidia in airtight and water-impermeable zipper-lock bags for long-term storage. An average of approximately 1.83 grams of dry Metarhizium robertsii conidia was harvested from the flaked barley substrate, whereas zero Metarhizium pinghaense was harvested from the substrate. No dry fungal conidia were harvested from the flaked oat substrate for either Metarhizium species.A significant difference was observed between the two species of Metarhizium in the estimated average conidia per gram harvested from the rice grains. Metarhizium robertsii had slightly higher average conidia count per gram than Metarhizium pinghaense. No significant difference was observed between the two species of Metarhizium in the estimated number of conidia present on the spent rice substrate.However, Metarhizium pinghaense had slightly higher conidia on the rice substrate than Metarhizium robertsii No significant difference is estimated in the two species of Metarhizium in their overall conidia yield obtained from the rice substrate cultures. However, Metarhizium pinghaense produced a slightly higher conidia yield than did Metarhizium robertsii, which produced a lower conidial yield. The challenging part of this technique is the substrate contamination through inoculation with a contaminated blastospores inoculum.Thus, always ensure sterility while working. This demonstration helps the students efficiently reproduce the technique without clumsy mistakes that can result in the termination of the entire process.

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