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Our current knowledge on bacterial cadmium (Cd) resistance is mainly based on the functional exploration of specific Cd-resistance genes. In this study, we carried out a genomic study on Cd resistance of a newly isolated Cellulomonas strain with a MIC of 5 mM Cd. Full genome of the strain, with a genome size of 4.47 M bp and GC-content of 75.35%, was obtained through high-quality sequencing. Genome-wide annotations identified 54 heavy metal-related genes. Four potential Cd-resistance genes, namely zntAY8, copAY8, HMTY8, and czcDY8, were subjected to functional exploration. Quantitative PCR determination of in vivo expression showed that zntAY8, copAY8, and HMTY8 were strongly Cd-inducible. Expression of the three inducible genes against time and Cd concentrations were further quantified. It is found that zntAY8 responded more strongly to higher Cd concentrations, while expression of copAY8 and HMTY8 increased over time at lower Cd concentrations. Heterologous expression of the four genes in Cd-sensitive Escherichia coli led to different impacts on hosts’ Cd sorption, with an 87% reduction by zntAY8 and a 3.7-fold increase by HMTY8. In conclusion, a Cd-resistant Cellulomonas sp. strain was isolated, whose genome harbors a diverse panel of metal-resistance genes. Cd resistance in the strain is not controlled by a dedicated gene alone, but by several gene systems collectively whose roles are probably time- and dose-dependent. The plasmid-free, high-GC strain Y8 may provide a platform for exploring heavy metal genomics of the Cellulomonas genus.

Biodegradation of reactive azo dyes has been an arduous problem for decades. Several efficient biosystems have been proposed for dye degradation, but most of them are dependent on the availability of costly co-substrates such as peptone, yeast extract, and/or glucose. The present study describes the azo dye degradation by a bacterial consortium using glycerol as a sole co-substrate. The consortium was developed from a mixed bacterial culture obtained upon enrichment of soil sediment for Reactive Blue 28 (RB28) decolorization in the presence of glycerol (0.1%; v/v). The consortium with three bacterial species, i.e., Stenotrophomonas acidaminiphila APG1, Cellulomonas sp. APG4, and Pseudomonas stutzeri APG2, designated as “SCP,” decolorized 92% of 100 ppm dye in 96 h. The intricacies of the interactions existing within the members of the consortium were resolved by a simple and unique analysis called “BSocial.” Among all the members, Cellulomonas sp. APG4 exerted a net-positive impact for decolorization (%) on the consortium. The net fitness of the community increased when all the three species were present, and thus, all of them were selected for further analysis. Moreover, APG4 seemed to be central in the reductive decolorization as it possessed the highest reductase activity. The dye degradation by the consortium was demonstrated by UV-Visible spectroscopy, HPTLC, and FTIR spectroscopy of control and decolorized cell-free supernatant. The LC-ESI-MS analysis of metabolites extracted from decolorized cell-free medium led to the identification of degradation products, thus leading us to propose the plausible pathway for degradation of RB28 by bacterial consortium. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s42770-020-00303-3) contains supplementary material, which is available to authorized users.

The genome information will be useful for studies of microbial enzymes for industrial application in lignocellulosic biomass utilization. Fil: Piccinni, Florencia Elizabeth. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Murua, Yanina. Universidad Argentina de la Empresa. Facultad de Ingeniería y Ciencias, Exactas; Argentina Fil: Talia, Paola Mónica. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Ghio, Silvina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Suelos; Argentina Rivarola, Maximo Lisandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Campos, Eleonora. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Biotecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

We present the genome of the cellulose-degrading Cellulomonas sp. strain FA1 isolated from an actively serpentinizing highly alkaline spring. Knowledge of this genome will enable studies into the molecular basis of plant material degradation in alkaline environments and inform the development of lignocellulose bioprocessing procedures for biofuel production.

An objective of this study was to develop high cellulase-producing bacteria by mutagenesis and optimization studies. Among 328 mutant strains of Cellulomonas sp. TSU-03, the mutant M23, NTG mutant, gave the highest value of cellulase activity 2008 U/mg protein) followed by mutant M17 (1884 U/mg protein) in CMC medium. The optimum medium and environmental conditions for cellulase production consisted of 4% wastepaper, 1% NaNO3 under cultivation temperature at 35°C with initial pH and agitation speed at 6 and 100 rpm, respectively. Cellulomonas sp. strain M23 produced the highest cellular growth (28.09 ± 2.28 g/L) and FPase, CMCase as well as, β-glucosidase activities at 325, 2420 and 152 U/mg protein, respectively. Under optimal condition, the cellulase activity achieved from strain M23 is 1.28- and 1.30-fold higher than cellulase from mutant M17 and wild type, respectively. After being subcultured 12 times, the cellulase production of the mutant M23 was stable. The results suggested that Cellulomonas sp. M23 had a good potential for production of cellulase by fermentation using a cultivation medium containing wastepaper as the main substrate. Key words: Mutagenesis, NTG, Ultraviolet, Wastepaper.

Two-hundred and twenty-five mangrove bacterial strains previously isolated from several mangrove areas in the Philippines were qualitatively screened for cellulase production and 154 were found to be capable of cellulase production. Among them, ten strains showed very strong positive cellulase activities, which were then quantified. Five with the statistically highest activities, specifically, BBCS-11, BBCS-14, BBoB2L2-2, BOrMGS-2, and BOrMGS-3, including Cellulomonas sp. BIOTECH 1240 (control), were further subjected to partial optimization studies. The effects of substrate, pH, incubation temperature and incubation time on cellulase productoin were determined. The cellulase activities (U mL -1 ) of the strains under optimized conditions were: 54.80 (Control); 56.60 (BBCS-11); 66.50 (BBCS-14); 50.33 (BBoB2L2-2); 51.04 (BOrMGS-2); and 48.70 (BOrMGS-3). The promising cellulase producers were previously identified: BBCS-11 as Bacillus cereus; BBCS-14 as Bacillus licheniformis; BOrMGS-2 and BOrMGS-3 as Bacillus pumilus; and BBoB2L2-2 as Bacillus sp.

Cellulose degrading bacteria were isolated from the intestinal fluid of the silver cricket Lepisma Sp. and a culture was developed anoxigenically in the cellulose degrading medium following standard laboratory techniques. The cellulolytic activity of the microbe was examined in a broth culture using Whatman 42 filter paper as the source of insoluble cellulose. Activity was measured spectrophotometrically (620nm) following Anthrone reaction of the culture filtrate and the sugar produced was quantified as a factor of time. The pH optimum was found to be between 7 and 8. Temperature profile optimum was between 30–37°C. The microbes appeared as white colonies on a solid medium. Morphologically the bacterium is a gram-positive nonspore forming rod which was tentatively identified as a new strain of Cellulomonas sp.

The reduction of Cr(VI), Fe(III), and U(VI) was studied using three recently isolated environmental Cellulomonas sp. (WS01, WS18, and ES5) and a known Cellulomonas strain ( Cellulomonas flavigena ATCC 482) under anaerobic, non-growth conditions. In all cases, these cultures were observed to reduce Cr(VI), Fe(III), and U(VI). In 100 h, with lactate as electron donor, the Cellulomonas isolates (500 mg/l total cell protein) reduced nitrilotriacetic acid chelated Fe(III) [Fe(III)-NTA] from 5 mM to less than 2.2 mM, Cr(VI) from 0.2 mM to less than 0.001 mM, and U(VI) from 0.2 mM to less than 0.12 mM. All Cellulomonas isolates also reduced Cr(VI), Fe(III), and U(VI) in the absence of lactate, while no metal reduction was observed in either the cell-free or heat-killed cell controls. This is the first report of Cellulomonas sp. reducing Fe(III) and U(VI). Further, this is the first report of Cellulomonas spp. coupling the oxidation of lactate, or other unknown electron donors in the absence of lactate, to the reduction of Cr(VI), Fe(III), and U(VI).

A cellulolytic bacterium has been isolated from soil and identified as a Cellulomonas sp. Optimization of media components and environmental factors led to a 17-fold increase in cellulase activity within 40 h. The trace elements Zn2+, Co2+ and Cu2+ caused severe inhibition, which could be reduced by the addition of EDTA. The enzymes endoglucanase, exoglucanase and xylanase were always present irrespective of the carbon source used.