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Isolation, optimization, and purification of extracellular levansucrase from nonpathogenic Klebsiella strain L1 isolated from waste sugarcane bagasse

Desai, Maitri, Patel, Kartik
Biocatalysis and agricultural biotechnology 2019 v.19 pp. 101107
Klebsiella, agar, blood, carbon, culture media, fermentation, levan, levansucrase, molecular weight, nitrogen, pH, polyacrylamide gel electrophoresis, polymers, ribosomal RNA, sequence analysis, sodium chloride, sucrose, sugarcane bagasse, temperature, thin layer chromatography, wastes, yeast extract
A newly isolated acidophilic bacterial strain from waste sugarcane bagasse was identified as Klebsiella species by biochemical and 16S rRNA sequencing methods. Klebsiella sp. strain L1 was selected for its ability to produce extracellular levansucrase. The optimization of carbon source, nitrogen source, sucrose concentration, NaCl concentration, initial pH and temperature of the growth medium in the flask fermentation medium. In the investigation, sucrose acts as a superior carbon source whereas yeast extract act as the best nitrogen source for Klebsiella sp. strain L1. 10% sucrose concentration and 2% sodium chloride (NaCl) concentration act as an inducer for levansucrase production. Isolate growing and produce optimum levansucrase under acidic condition (pH 5.0) with normal temperature range (40 °C). Synthesis of levan polymer by isolate was detected using thin layer chromatography (TLC) plate method. SDS PAGE result shown that the molecular weight of levansucrase from Klebsiella sp. strain L1 was 43 kDa. Moreover, isolate has a γ-hemolysis reaction on blood agar which indicated their non-pathogenic nature.