A novel thermostable xylanase of Paenibacillus macerans IIPSP3 isolated from the termite gut

Abstract

Xylanase is an enzyme in high demand for various industrial applications, such as those in the biofuel and pulp and paper fields. In this study, xylanase-producing microbes were isolated from the gut of the wood-feeding termite at 50°C. The isolated microbe produced thermostable xylanase that was active over a broad range of temperatures (40-90°C) and pH (3.5-9.5), with optimum activity (4,170 ± 23.5 U mg⁻¹) at 60°C and pH 4.5. The enzyme was purified using a strong cation exchanger and gel filtration chromatography, revealing that the protein has a molecular mass of 205 kDa and calculated pI of 5.38. The half-life of xylanase was 6 h at 60°C and 2 h at 90°C. The isolated thermostable xylanase differed from other xylanases reported to date in terms of size, structure, and mode of action. The novelty of this enzyme lies in its high specific activity and stability at broad ranges of temperature and pH. These properties suggest that this enzyme could be utilized in bioethanol production as well as in the paper and pulp industry.

Purification and Characterization of Alkaline Xylanase Secreted from <i>Paenibacillus macquariensis</i>

“…This bacteria secreted xylanase enzyme as tested by Congo red dye staining method [15]. There are other reports also indicating secretion of xylanase by Paenibacillus species [16,17]. Therefore, the bacteria is capable of degrading xylan, xylanase being a xylan degrading enzyme.…”

Agrowastes as Feedstock for the Production of Endo-β-Xylanase from <b><i>Cohnella</i></b> sp. Strain AR92

“…AR92, probably due to catabolic repression as also observed for the related Paenibacillus sp. [Dheeran et al, 2012;Fukuda et al, 2010]. In contrast, the lignocellulosic substrates OH-SCB and HC-SCB were the most effective sources for enzyme production by Cohnella sp.…”

Cellulomonas sp. Isolated from Termite Gut for Saccharification and Fermentation of Agricultural Biomass

“…The bodies of termites were ground and serially diluted with Milli Q water. The dilute sample was spread over nutrient agar media with 1% carboxymethyl cellulose (CMC) and 1% beechwood xylan provided by M. S. Traders (Sigma, Lahore, Pakistan) (Dheeran et al 2012;Pourramezan et al 2012). The plates were incubated at 30 C for 24 h.…”

“…The purified bacterial colonies were screened by the Congo red dye method using 0.2% CMC or 0.2% xylan separately (Dheeran et al 2012). The bacteria were incubated at 30 C for 48 h. Clear zones around the bacterial colonies established their ability to degrade cellulose and xylan (Liang et al 2014).…”

“…Two enzyme production media containing nutrient broth with 1% CMC and 1% xylan, pH 6.8 to 7.2 (Dheeran et al 2012;Bashir et al 2013) were prepared. The media were inoculated with termite gut bacteria 31 (TGB31) and incubated at mild rotation for 48 h at 30 C.…”