Bioconversion and saccharification of some lignocellulosic wastes by Aspergillus oryzae ITCC-4857.01 for fermentable sugar production

The recent interest in bioconversion of agricultural and industrial wastes to chemical feedstock has led to extensive studies on cellulolytic enzymes produced by microorganisms. In the present study three lignocellulosic substrates viz. sugarcane bagasse, sawdust and water hyacinth were pre-treated with alkali and enzyme and their effect on bioconversion has been investigated. The ability of selected substrates for induction of cellulase enzyme by A. oryzae ITCC 4857.01 and for the potentiality of the induced enzyme to saccharify the substrates were also assessed. The maximum degree of conversion of substrate (0.415%) and improved specific substrate consumption (0.99 g substrate/g dry biomass) was exhibited in sugarcane bagasse after alkali treatment at 96 hrs. Both alkali-treatment and enzyme-treatment, water hyacinth was the best for cellulase induction and showed maximum endoglucanase activity of 11.42 U/ml. Reducing sugar yield ranged from 1.12 mg/ml for enzyme treated sawdust at 48 hrs to 7.53 mg/ml for alkali treated sugarcane bagasse at 96 hrs. Alkali-treated sugarcane bagasse gave the highest saccharification rate of 9.03% after 96 hrs. The most resistant substrate was sawdust which produced 5.92% saccharification by alkaline treatment. The saccharification of lignocellulosic substrates by enzyme produced by A. oryzae ITCC 4857.01 indicates the enzymes specificity towards the substrates. The use of such enzyme in lingo-cellulose hydrolysis will lead to efficient conversion of cellulose materials to other important products

INHIBITORY EFFECT OF DIFFERENT PLANT EXTRACTS, COW DUNG AND COW URINE ON CONIDIAL GERMINATION OF BIPOLARIS SOROKINIANA

Inhibition of conidial germination of Bipolaris sorokiniana was tested using eight ethanolic plant extracts, ten aqueous plant extracts in combination with cow dung and five aqueous plant extracts in combination with cow urine. Hundred percent of conidial germination was inhibited with the application of ethanolic extracts of Adhatoda vasica (leaf) and Zingiber officinale (rhizome) at 2.5 % concentration. After the treatment with Vinca rosea, Piper betle and Azadirachta indica extracts in combination with cow dung suspension showed 100 % inhibition of conidial germination; where the lowest was noted in case of Rauwolfea serpentina (30%) extract at same concentration. At 2.5 % concentration of Calotropis procera extracts in combination with cow urine, 91 % inhibition of conidial germination was observed. In most cases, Ocimum sanctum extract exhibited less inhibitory effect against B. sorokiniana