One-Pot Ionic Liquid-Mediated Bioprocess for Pretreatment and Enzymatic Hydrolysis of Rice Straw with Ionic Liquid-Tolerance Bacterial Cellulase

Ionic liquid (IL) pretreatment of lignocellulose is an efficient method for the enhancement of enzymatic saccharification. However, the remaining residues of ILs deactivate cellulase, therefore making intensive biomass washing after pretreatment necessary. This study aimed to develop the one-pot process combining IL pretreatment and enzymatic saccharification by using low-toxic choline acetate ([Ch][OAc]) and IL-tolerant bacterial cellulases. Crude cellulases produced from saline soil inhabited Bacillus sp. CBD2 and Brevibacillus sp. CBD3 were tested under the influence of 0.5–2.0 M [Ch][OAc], which showed that their activities retained at more than 95%. However, [Ch][OAc] had toxicity to CBD2 and CBD3 cultures, in which only 32.85% and 12.88% were alive at 0.5 M [Ch][OAc]. Based on the specific enzyme activities, the sugar amounts produced from one-pot processes using 1 mg of CBD2 and CBD3 were higher than that of Celluclast 1.5 L by 2.0 and 4.5 times, respectively, suggesting their potential for further application in the biorefining process of value-added products.

Isolation, Screening and Production of Bacterial Cellulase from Cow Dung

Cellulases are the most important industrial enzyme due to their potential application in various industries including pulp and paper, textile, laundry, biofuel production, food and feed industry, brewing and agriculture. The present study was carried out to isolate and characterize cellulase producing microorganisms from different cow dung samples. Four different cow dung samples were collected from variety of cows namely Gir, Holstein, Jersey and Desi and isolation and screening was done to check cellulase producing microorganisms. The obtained 11 isolates were screened for their cellulase activity by using CMC (carboxymethyl cellulose) agar medium. In the current study, 10 cellulase producing isolates were obtained and were characterized morphologically from which 8 isolates were found Gram negative and 2 were found Gram positive. All the 10 cellulase producers were further confirmed for their cellulase producing ability by performing turbidity test. Out of these 10 isolates, GN4 and HN2 with optical density 0.35 and 0.28, respectively were found to be best cellulase producer and were selected for cellulase enzyme production and other further studies. Botssh the isolates were tested for their enzymatic activities by performing DNSA method and protein estimation by Lowry’s method. Cellulase activities were found to be 7.33 µg/ml/min and 3.66 µg/ml/min and the total protein concentrations were found to be 40 µg/ml and 32 µg/ml for GN4 and HN2, respectively. Thus, dungs cow dung can be considered as the excellent source for cellulase producing bacteria.

Potential Detergent Compatibility And De-staining Ability Of Cellulolytic Bacteria

Cellulases are inducible enzymes that are synthesized by many microorganisms during their growth on cellulosic materials. Production of cellulase enzyme from bacteria has gained interest for applications in industries owing to their stability, catalytic activity and ease of production. In current study, total 40 cellulolytic bacteria were screened by agar well diffusion assay followed by Congo red stain. Cellulolytic bacteria were evaluated for detergent compatibility and de-staining ability. Bacterial cellulase production was optimized at different environmental conditions. Biochemical testing was done following Bergey’s manual. Ten cellulolytic bacteria selected, were gram positive. Bacteria showed best cellulolytic activity at 40oC to 60oC, at pH 9, lactose as carbon source and peptone as nitrogen source. Best hydrolysis zone shown was 45mm from strain MS22 and least zone was 6mm. The maximum detergent activity for surf excel was observed for G2 while the lowest was observed for MW22. Similarly, maximum activity for ariel and bonus were observed for RS5 and C3. G1 and C3 showed better clearance of ink as compared to other strains. In de-staining, G1, C1and MW17 showed better clearance of edible oil and G1, C2 and MW18 showed better clearance of grease. These promising cellulolytic bacteria can be used for various applications in different industries.

CELLULASE AND ITS ROLE IN INDUSTRIES: A REVIEW

Cellulose is the most abundant polymer present in various agricultural wastes. These wastes can be converted into useful products by degradation of cellulose present inside these wastes. The conversion is catalysed by cellulase enzyme. This review describes the bacterial cellulase enzyme including their classification, isolation, production and applications. In this, we have mentioned the isolation and screening techniques of bacterial cellulase along with some other microbial species, which are having potential of producing cellulase enzyme. It also discusses the submerged and solid-state production of cellulase enzyme along with applications in textile, paper, production of biofuel, food and animal feed industry, oil extraction, brewing, and agriculture. Now a days, industrial enzymes achieved a great place due to their easy production from cheap agricultural wastes together with their magnificent role in above mentioned industries. These features attract the industries, so that they can make their products economically valuable and also improve the protocols accordingly.

Correction to: A downstream box fusion allows stable accumulation of a bacterial cellulase in Chlamydomonas reinhardtii chloroplasts

In the original version of the article [1], a calculation error resulted in a 3-order of magnitude mistake for the y-axis of the data reported in Fig. 5c and d.