Optimization and molecular identification of novel cellulose degrading bacteria isolated from Egyptian environment

Abstract

Cellulase producing bacteria were isolated from both soil and ward poultry, using CMC (carboxymethylcellulose) agar medium and screened by iodine method. Cellulase activity of the isolated bacteria was determined by DNS (dinitrosalicylic) acid method. The highly cellulolytic isolates (BTN7A, BTN7B, BMS4 and SA5) were identified on the basis of Gram staining, morphological cultural characteristics, and biochemical tests. They were also identified with 16S rDNA analysis. The phylogenetic analysis of their 16S rDNA sequence data showed that BTN7B has 99% similarity with Anoxybacillus flavithermus, BMS4 has 99% similarity with Bacillus megaterium, SA5 has 99% homology with Bacillus amyloliquefaciens and BTN7A was 99% similar with Bacillus subtilis. Cellulase production by these strains was optimized by controlling different environmental and nutritional factors such as pH, temperature, incubation period, different volumes of media, aeration rate and carbon source. The cellulase specific activity was calculated in each case. In conclusion four highly cellulolytic bacterial strains were isolated and identified and the optimum conditions for each one for cellulase production were determined. These strains could be used for converting plant waste to more useful compounds.

Saccharification of macroalgal polysaccharides through prioritized cellulase producing bacteria

“…Enzymes secreted by these microorganisms are feasible for large scale production due to their broad biochemical diversity, with the possibility of generating mass cultures and also ease of genetic manipulation ( Zhang and Kim, 2010 ). Annexure I lists the different sources used in the earlier studies ( Mutalik et al, 2012 ; Erasmus et al, 1997 ; Hakamada et al, 1997 ; Li et al, 2003 ; Verma et al, 2012 ; Lo et al, 2009 ; Hussain et al, 2017 ; Liang et al, 2009 ; Gupta et al, 2012 ; Salah et al, 2007 ; Gao et al, 2008 ; Ojumu et al, 2003 ; Bajaj et al, 2003 ; Liang et al, 2014 ; Mata et al, 2010 ; Ventura and Castañón, 1998 ; Antonio et al, 2010 ; Gautam et al, 2011 ; Bairagi et al, 2002 ; Dar et al, 2015 ; Philip et al, 2016 ; Kamara et al, 2008 ; Reddy et al, 2003 ; Krishna, 1999 ; Dabhi et al, 2014 ; Maki et al, 2011 ) about the successful isolation of cellulose degrading bacteria.…”

Whole genome sequence of Serratia marcescens 39_H1, a potential hydrolytic and acidogenic strain

“…Five microliters of overnight grown culture of strain 39_H1 was spot plated on carboxymethyl cellulose (CMC) agar plates for characterization cellulose degradability of the isolate. The CMC comprised of 0.1 % K 2 HPO 4 ; 0.05 % MgSO 4 ; 0.05 % CaCl 2 ; 0.2 % CMC; 0.02 % bacteriological peptone; 0.2 % NaNO 3 ; 1.5 % bacteriological agar, 1 l of distilled water and at pH 7 [ 18 , 19 ]. Inoculated plates were incubated at 37 °C for 72 h and flooded with Gram’s iodine (2 g KCl; 1 g Iodine in 0.3 l of distilled water) for 3-5 min after incubation.…”

Improvement of cellulose degradation by cloning of endo-β-1, 3-1, 4 glucanase (bgls) gene from Bacillus subtilis BTN7A strain

“…Bacillus subtilis subsp. subtilis BTN7A is a highly cellulolytic strain isolated by the research team from Egypt [11], GenBank accession number KC438368. E. coli DH5α was used for transformation.…”

“…Different cellulolytic bacterial strains have been collected and isolated including different B. subtilis strains among them B. subtilis subsp. subtilis BTN7A strain which was isolated from Egypt environment had the highest cellulase activity [10], [11]. Among the possible ways to produce high production of cellulases, different attempts have been made to clone and express the genes encoding for cellulases in a heterologous host, E. coli [13], [1].…”