Open AccessExtra and intracellular laccase titers of xylophagic bacteria isolated from adult termite
Author(s) -
Luciana Furlaneto-Maia,
Sérgio Luis Mendes Hoyos,
Alex Kiyomassa Watanabe,
Alane Tatiana Pereira Moralez,
Márcia Cristina Furlaneto,
Juliana Feijó de Souza Daniel
Publication year - 2021
Publication title -
acta scientiarum. technology/acta scientiarum. technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.183
H-Index - 17
eISSN - 1807-8664
pISSN - 1806-2563
DOI - 10.4025/actascitechnol.v43i1.51805
Subject(s) - laccase , guaiacol , abts , extracellular , bacteria , fermentation , chemistry , microbiology and biotechnology , food science , biology , biochemistry , enzyme , dpph , genetics , antioxidant
Laccase is an important enzyme in terms of its versatile applicability, but its commercial use is limited by factors such as high production cost, low activity and/or stability under given conditions. The objective of this study was to screen xylophagic bacteria isolated from termites for the production of extracellular and intracellular laccases. Six laccase-positive strains were isolated, namely CA, A3, A5, A6, A7 and A8. They were molecularly identified by sequence analysis of 16S rRNA and classified under the genera Bacillus (A7, A8, CA) and Pseudomonas (A3, A5, A6). Laccase was produced by these bacterial isolates by submerged fermentation and was optimized at 37°C, pH 5.5, 6.2 and 7.0, with agitation and 0.5 mM guaiacol (as carbon source). Laccase activity was determined by measuring the oxidation of guaiacol and ABTS (2,21-azino bis[3-ethylbenzthiazoline-6-sulfonate]). Strain A5 produced extracellular laccase titers ranging from 123 to 168 U ml-1. Guaiacol was identified as a better substrate for the quantification of laccase. In conclusion, bacteria harboring the gut of termites can produce extracellular laccase with activity at medium to moderate acidity.