A low-cost approach for the generation of enhanced sugars and ethanol from rice straw using in-house produced cellulase-hemicellulase consortium from A. niger P-19

Cocktail of carbohydrases from Aspergillus niger: an economical and eco-friendly option for biofilm clearance from biopolymer surfaces

“…From these results it could be inferred that the enzymes do not have bactericidal activity but simply disperse the biofilm cells into their planktonic state by disrupting the biofilm architecture. These results are in concordance with our earlier study (Kaur et al 2020a , b ) wherein a significant reduction in the biofilm-biomass (based on crystal violet assay) was recorded after enzyme treatment. Other workers have also reported dispersal of biofilms by enzymatic action and EPS degradation (Kalpana et al 2012 ; Fleming and Rumbaugh 2018 ).…”

“…In our earlier study (Kaur et al 2020a , b ), we have reported the effect of various cultural and environmental factors by ‘one variable at a time’ (OVAT) method. However, when these factors are used in combination, then one factor might influence the effect of other factor.…”

“…Earlier also cellulases and hemicellulases from various fungi have been reported to have a temperature optima between 50 and 65 °C e.g. mannanase from Trichoderma reesei and Rhizopus oryzae (Kupski et al 2014 ), Lichtheimia ramose (Garcia et al 2018 ), Aspergillus niger P-19 (Kaur et al 2020b ). Majority of cellulases and xylanases from thermophiles have been reported to have temperature optima between 50 and 80 °C (Bala and Singh 2019 ).…”

“…Endoglucanase, β-glucosidase and xylanase from A. niger strain were found to have half lives of 43 h, 148 h and 90 h respectively (Farinas et al 2010 ). Recently, a study carried in our laboratory reported highly stable cellulases and hemicellulases from A. niger P-19, retaining residual activity up to 408 h at 50–60 °C (Kaur et al 2020b ). Like temperature, pH also greatly affect the enzyme activities, since any change in pH results in alteration in the ionic character of enzyme which in turn affects both the catalytic site and conformational status of the enzyme (Prakash et al 2009 ).…”

“…Sinitsyn et al ( 2014 ) reported optimal cellulose and hemicellulase activities from Penicillium verruculosum in the pH range of 3.5 to 5.5. Cellulases and hemicellulases produced by Lichtheimia ramosa and A. niger P-19 were found to be optimally active in the pH range of 4.5–5.5 (Garcia et al 2018 ) and pH 4.0 (Kaur et al 2020b ) respectively. In our study, all the enzymes in the cocktail were found to be active over a wide pH range, which is a favourable finding as the cocktail can be utilized for biofilm dispersal under diverse conditions.…”