Hyper-Production of Laccase By Pseudomonas putida LUA15.1 through Mutagenesis

Extracellular laccase production and phenolic degradation by an olive mill wastewater isolate

“…The OMWW isolate (Acinetobacter REY) was inoculated into Erlenmeyer flasks containing 100 mL of sterile tryptone yeast broth (TYB) containing 0.15% yeast extract (RM027, Himedia), 0.15% tryptone (Tryptone type-1 RM014, Himedia) and 0.5% sodium chloride as described earlier by Dalfard et al, (2006). The bacterial biomass was measured after 0, 24, 48, 72 h under shaking (100 rpm) at 37 °C, as described above, and the culture supernatant was collected after centrifugation at 10000 rpm for 10 min at 4 °C for extracellular laccase assay (Verma et al, 2016). In order to characterize the effect of inducers on laccase production by the isolate, treatments containing 200 µmol/L CuSO 4 •5H 2 0 alone (Kuddus et al, 2013;Sondhi et al, 2015;Verma et al, 2016) and 200 µmol/L CuSO 4 •5H 2 0 with 50 mg/L phenols were performed.…”

“…The bacterial biomass was measured after 0, 24, 48, 72 h under shaking (100 rpm) at 37 °C, as described above, and the culture supernatant was collected after centrifugation at 10000 rpm for 10 min at 4 °C for extracellular laccase assay (Verma et al, 2016). In order to characterize the effect of inducers on laccase production by the isolate, treatments containing 200 µmol/L CuSO 4 •5H 2 0 alone (Kuddus et al, 2013;Sondhi et al, 2015;Verma et al, 2016) and 200 µmol/L CuSO 4 •5H 2 0 with 50 mg/L phenols were performed. Sterile controls contained 100 mL of TYB (with and without inducer) without the addition of the isolate.…”

“…The enzyme assay was performed on the filtrate supernatant using 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS) (Sigma, Israel) as the substrate for laccase activity, as described earlier (Tahmasbi et al, 2016), with some modifications. The per mL assay mixture consisted of 200 μL of crude extracellular filtrate (enzyme source) and 800 μL aliquots of 1 mmol/L ABTS prepared in a 0.1 mol/L sodium acetate buffer (pH 4.5) (Verma et al, 2016). The oxidation of ABTS was monitored by determining the increase in absorbance at 420 nm (ε420, 36000 L/(mol.cm) at a path length of 1 cm) after incubation at 32 °C for 10 min.…”

“…LBC1, P. putida LUA15.1, Escherichia coli, Bacillus halodurans, B. subtilis SF, Bacillus sp. HR03, Azospirillum lipoferum, P. desmolyticum NCIM 2112, B. pumilus and B. subtilis WP1 (Kuddus et al, 2013;Muthukumar and Murugan, 2014;Verma et al, 2016). Most bacterial laccases are stable, highly thermo-tolerant and maintain their activity under neutral to alkaline conditions.…”

Pseudomonas extremorientalis BU118: a new salt-tolerant laccase-secreting bacterium with biotechnological potential in textile azo dye decolourization

“…Laccases from plant and fungal sources, especially white-rot fungi, have been studied extensively (Arora and Sharma 2010 ; Skariyachan et al 2016 ). However, laccases have been discovered in a small number of bacteria including Bacillus subtilis , Bordetella campestris , Caulobacter crescentus , Escherichia coli , Mycobacterium tuberculosis , Pseudomonas syringae , P. aeruginosa , P. putida , P. fluorescens , Yersinia pestis and Stenotrophomonas maltophilia (Claus 2003 ; Sharma et al 2007 ; Imran et al 2012 ; Kuddus et al 2013 ; Vandana and Peter 2014 ; Verma et al 2016 ). These bacterial laccases have the ability to perform the activity at crucial conditions like in the presence of high salt concentrations and even at alkaline pH values (Margot et al 2013 ).…”