Isolation and cultivation of xylanolytic and cellulolytic Sarocladium kiliense and Trichoderma virens from the gut of the termite Reticulitermes santonensis

Abstract

The purpose of this work was the isolation and cultivation of cellulolytic and xylanolytic microorganisms extracted from the gut of the lower termite Reticulitermes santonensis. Microcrystalline cellulose (with and without lignin) and beech wood xylan were used as diets instead of poplar wood in order to select cellulose and hemicellulose-degrading fungi. The strain Sarocladium kiliense (Acremonium kiliense) CTGxxyl was isolated from the termites fed on xylan, while the strain Trichoderma virens CTGxAviL was isolated from the termites fed on cellulose (with and without lignin). Both molds were cultivated in liquid media containing different substrates: agro-residues or purified polymers. S. kiliense produced maximal β-glucosidase, endo-1,4-β-D-glucanase, exo-1,4-β-D-glucanase and endo-1,4-β-D-xylanase activities of 0.103, 3.99, 0.53, and 40.8 IU/ml, respectively. T. virens produced maximal β-xylosidase, endo-1,4-β-D-glucanase, exo-1,4-β-D-glucanase, and endo-1,4-β-D-xylanase activities of 0.38, 1.48, 0.69, and 426 IU/ml. The cellulase and the xylanase of S. kiliense, less common than T. virens, were further investigated. The optimal activity of the xylanase was observed at pH 9-10 at 60 °C. The cellulase showed its maximal activity at pH 10, 70 °C. Zymography identified different xylanases produced by both molds, and some fragment sizes were highlighted: 35, 100, and 170 kDa for S. kiliense and 20, 40, 80, and 170 kDa for T. virens. In both cases, endo-1,4-β-D-xylanase activities were confirmed through mass spectrometry.

Screening of bacterial extracellular xylanase producers with potential for cellulose pulp biobleaching

“…Bacillus species isolate TC-DT13 thus can utilize less expensive substrates which induces the production of xylanases. Compared to other studies using this waste, such as those by Tarayre et al (2013), Guan, Zhao, Zhao, Wang, Huo, Cui, and Jiang (2016) and Ping et al (2018), the results obtained in this study demonstrated higher xylanase activity at the maximum xylanolitic levels identified in prior the previous studies were 44.3 U mL -1 , 52.94 U mL -1 and 57.25 U mL -1 , respectively, using wheat bran.…”

Trichoderma atroviride 102C1: A promising mutant strain for the production of a -glucosidase, -xylosidase and -L-arabinofuranosidase activities using agroindustrial by-products

“…Trichoderma reesei RUT C30, for instance, when grown on cellulose 1% (w/v) for 7 days, have shown maximal enzyme activity of 0.25 U.mL -1 (Jiang et al, 2011). Trichoderma virens CTGxAviL, also grown on -cellulose + xylan beechwood, after 3 days, have produced activities of 0.38 U.mL -1 (Tarayre et al, 2015). Other fungal strains, as Aspergillus awamori (Paredes et al, 2015), for instance, have also shown very low results when grown on agro-industrial residues.…”

In silico mining for alkaline enzymes from metagenomic dna data of gut microbes of the lower termite Coptotermes gestroi in Vietnam

“…However, many studies demonstrated that cellulolytic and hemicellulolytic enzymes from microorganism in termite gut is quiet rich [11] such as: 73% cellulases and xylanases were known in Microcerotermes sp. [27]; the series of cellulase in the foregut/salivary gland; and a rich diversity of derived GHFs in the hindgut. Of the various exoglucanases are undeniably the most diverse [23].…”

“…have wider optimal pH range of 5.0-10.0. In case of cellulolytic and hemmicellulolytic enzymes of Sarocladium kiliense and Trichoderma virens isolated from the gut of the lower termite, R. santonensis, optimal pH range was pH 9-10 [27]. In the higher termite, Nasutitermes corniger, pH of the gut reaches as high as 11 [10].…”