Strains of Bacillus thuringiensis (Bt) are known to produce crystalline proteins (δ-endotoxins) concomitantly with sporulation during their stationary phase of growth, which are demonstrated as lethal to lepidopeterous, coleopeterous and dipterous insects in addition to mites, nematodes, protozoa and flukes. Upon ingestion, the δ-nascent endotoxin is an inactive protoxin complex of (Cry alone or Cry and Cyt toxins together) high molecular mass, which is cleaved upon ingestion into the active component proteins at the high alkaline environments in the digestive tract of these agricultural pests. Conventionally, Bt-crystals are being produced employing submerged or liquid fermentation techniques in commercial media, but recently many workers have used solid-state fermentation strategy for the enhanced production of Bt-toxin at low cost. Apart from δ-endotoxin, some isolates of Bt produce another class of insecticidal small molecules called β-exotoxin (thuringiensin), which may be harmful to humans. Moreover, resistance to Bt developed in various target pest is yet another concern for Bt-industry. Following a brief introduction, this review addresses various toxins produced by various strains of Bt, Bt production media and media formulations with emphasis to solid-state fermentation, general structure of Cry toxin, its mode of action, target pests, bioassay, resistance to Bt toxins and resistance management. Briefly, this review would provide the readers an overview on the general aspects of Bt toxin, its general structure and mechanism of action.

In this study we describe a novel dark-green strain of Trichoderma viride exhibiting complete ensemble of cellulase, hemicellulase and ligninase activities on specific plate assays. To assess the cellulase production in detail, basal salt medium (BSM) was fortified with synthetic (carboxymethyl cellulose (CMC), glucose, sucrose, dextrose, lactose or maltose) and natural (flours of banana, banana peel, jack seed, potato or tapioca) carbon as well as nitrogen (yeast extract, beef extract, peptone, NaNO 3 or NH 4 NO 3) sources. Temperature and pH optima were 28˚C and 4, respectively for the growth of the fungus in CMC-BSM with 137 U/mL cellulase activity, which was enhanced to 173 U/mL at 1.25% CMC concentration. Flours of potato and banana peel supported comparable yields of cellulase to that of CMC, while sodium nitrate was the preferred nitrogen source. The water soluble bluish-green pigment (a probable siderophore) extracted from the spores showed an absorption maximum at 292 nm. To sum up, the complete lignocellulolytic potential of this fungus offers great industrial significance, coupled with the production of a new pigment.

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This study describes a novel dark-green spore producing strain of Trichoderma harzianum exhibiting higher activities of cellulase, hemicellulase and ligninase on specific plate assays. To assess the cellulase production in detail, basal salt medium (BSM) was supplemented with synthetic [carboxymethyl cellulose (CMC), glucose, sucrose, dextrose, lactose or maltose] and natural (flours of banana, banana peel, jack seed, potato or tapioca) carbon as well as nitrogen (yeast extract, beef extract, peptone, NaNO 3 or NH 4 NO 3) sources. Temperature and pH optima were 28˚C and 4, respectively for the growth of the fungus in CMC-BSM with 146 U/ml cellulase activity. Flours of potato and banana supported comparable yields of cellulase to that of CMC (147 U/ml and 168 U/ml, respectively), while sodium nitrate was the preferred nitrogen source (150 U/ml). The water soluble yellowish-green pigment (a probable siderophore) extracted from the spores showed an absorption maximum at 414 nm. To comprise, this fungus shows the complete lignocellulolytic potential which offers great industrial significance, especially for the ethanol production from the lignocellulosic waste coupled with the production of a new pigment.

Owing to the production of alpha, beta and gamma amylase subtypes; starch degrading microbes, especially bacteria have an invincible role in the food, fermentation, textile and paper industries. Of them, α-amylases from Bacillus spp. have contributed tremendous advancements in bio-industry, especially in starch, detergent and pharmaceutical arena. Though general reviews are seen in literature on amylases, no focused review is available yet solely on α-amylases produced by Bacillus spp. Hence, this focused review on α-amylases from the genus Bacillus is designed in such a way that it should give a vivid picture on most of the aspects on bacillial α-amylases in a handy module with an industrial perspective. With a short introduction on amylases in general, α-amylases from various species of Bacillus reviewed herein encompasses production of α-amylases by submerged and solid-state fermentations; nutrients and other factors required for maximizing production; immobilization strategies for whole cells or purified enzyme; an overview on the molecular weight of the enzyme; followed by distinct sections for purification, characterization, stability and crystal structure; and concluded with a section on industrial applications of the α-amylases from Bacillus spp.