Biosynthesis and characterization of a thermostable, alkali-tolerant chitinase from Bacillus pumilus JUBCH08 displaying antagonism against phytopathogenic Fusarium oxysporum

Abstract

The present investigation highlights the process parameters influencing the submerged fermentation of chitinase by Bacillus pumilus JUBCH08, purification and characterization of the enzyme and determination of antagonistic activity of the bacterium against Fusarium oxysporum. Medium supplemented with 0.5 % chitin and peptone, at initial pH 8.0, when incubated at 35 °C for 72 h favored highest chitinase production. The enzyme was purified 25.1-fold to homogeneity. The chitinase was found to be thermostable and alkali-tolerant with maximum activity at pH 8.0 and 70 °C for 1 h. The molecular weight of chitinase was found to be 64 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Mg2+, Co2+, Ca2+ and Mn2+ improved the chitinase activity. The K m and V max values of the enzyme were 0.13 mg/ml and 38.23 U/ml, respectively. When subjected to dual plate assay, the bacterium showed 45 % antagonism against F. oxysporum. Thus, it could be inferred that cultural conditions strongly affected the chitinase production by B. pumilus JUBCH08. The enzyme being thermostable and best functional under alkaline conditions could be useful for the feed industry and related biotechnological applications. Inhibition of F. oxysporum by the culture through lytic mechanism indicates its potentiality as a biocontrol agent.

Chitinase Production from Locally Isolated Bacillus cereus GS02 from Chitinous Waste Enriched Soil

“…3). Similar results have been reported where maximum chitinase secretion was found after 48 hours of incubation [23,24]. The isolate GS02 showed production of chitinase within first 24 hours and reached to its maximum level after 48 hours of incubation.…”

“…6). Bhattacharya et al [23] also showed maximum production of chitinase by Bacillus sp. between the temperature 35 to 37°C.…”

Anticancer and antifungal efficiencies of purified chitinase produced from <i>Trichoderma viride</i> under submerged fermentation

“…This may be caused by the mechanical forces that can lead to vacuolation of older hyphal compartments, which may lead to weakened hyphae and/or enhancing hyphal fragmentation (Paul et al, 1994). A similar finding was obtained by Bhattacharya et al (2016) who recorded that maximum production of chitinase from Bacillus pumilus was at 120 rpm.…”

Chitinase: diversity, limitations, and trends in engineering for suitable applications

“…In agriculture, the inhibitory properties of chitinases are being harnessed for the biological control of pests and fungal diseases of plants. The control of fungal phytopathogens such as Trichoderma reesei [ 98 ], Colletotrichum gleosporoides [ 99 ], Phoma medicaginis [ 100 ], Rhizoctonia solani [ 101 ], Fusarium oxysporum [ 102 ], and Fusarium graminarium [ 103 ] has been reported.…”