Use of Spent Mushroom Substrate for Production of <I>Bacillus thuringiensis</I> by Solid-State Fermentation

Abstract

The aim of this study was to explore a cost-effective method for the mass production of Bacillus thuringiensis (Bt) by solid-state fermentation. As a locally available agroindustrial byproduct, spent mushroom substrate (SMS) was used as raw material for Bt cultivation, and four combinations of SMS-based media were designed. Fermentation conditions were optimized on the best medium and the optimal conditions were determined as follows: temperature 32 degrees C, initial pH value 6, moisture content 50%, the ratio of sieved material to initial material 1:3, and inoculum volume 0.5 ml. Large scale production of B. thuringiensis subsp. israelensis (Bti) LLP29 was conducted on the optimal medium at optimal conditions. High toxicity (1,487 international toxic units/milligram) and long larvicidal persistence of the product were observed in the study, which illustrated that SMS-based solid-state fermentation medium was efficient and economical for large scale industrial production of Bt-based biopesticides. The cost of production of 1 kg of Bt was approximately US$0.075.

A new formulation of Bacillus thuringiensis: UV protection and sustained release mosquito larvae studies

“…LLP29-M19 was obtained from mosquitocidal Bt LLP29 by repeated 19 times exposure to ultraviolet mutagenesis. Culex quinquefasciatus (Fafu strain), the mosquitoes used in bioassays, were collected from Fujian Agriculture and Forestry University, China and reared in our lab in a controlled environment room at 28 °C and 85% relative humidity (RH) with a photoperiod of 14:10 h (L:D)3.…”

“…It is the most widely produced microbial insecticide in the world, and has been used extensively in pest management in agriculture, forestry and public health primarily because of its safety to humans, livestock and the environment23. However, the spores and ICPs of Bt are susceptible to degradation when exposed to ultraviolet radiation in sun light, with water and other substances in the cell ionized.…”

Purification and Characterization of Xylanase from Spent Mushroom Compost and its Application in Saccharification of Biomass Wastes

“…The residual lignocellulosic substrates can be reused by some microorganisms (Wu et al 2014) or hydrolyzed into the fermentable sugars (Balan et al 2008;Wu et al 2013). Extracellular enzymes from SMC include cellulases, xylanases, and ligninases (Isikhuemhen and Mikiashvilli 2009;MayoloDeloisa et al 2009;Yang et al 2015), the activities and amounts of which depend on the mushroom species and its cultivation conditions.…”

Plant, Soil and Microbes

“…Introducing a consortium of diverse bacterial strains has been found to degrade a number of pollutants as each strain tends to employ a different catabolic pathway to detoxify the respective pollutant (Fuentes et al 2014 ). In addition to these strategies, genetically engineering the microbes and plants to produce transgenic varieties with greater or diverse ability to detoxify the environmental pollutants can be even more useful (Peng et al 2014 ;Mouhamad et al 2014 ;Jagtap and Bapat 2015 ). Transgenically produced tobacco plants, expressing the mammalian cytochrome P450 system, have been found to metabolize a number of pollutants including chloroform and trichloroethylene (Renault et al 2014 ).…”

“…MAMPs originate from benefi cial microbes, whereas PAMPs specifi cally describe molecules from phytopathogens (Henry et al 2012 ;Newman et al 2013 ). PAMPs or MAMPs are often only present in the microbes and not the hosts (Wu et al 2014 ). Thus, PAMPS are a subgroup of MAMPs (Maffei et al 2012 ).…”