Assessing water quality by ratio of the number of dominant bacterium species between surface/subsurface sediments in Haihe River Basin.

Sedimentary microorganisms can be used as a sensitive indicator of integrated aquatic environment quality assessment and indicate long-term water quality or toxicity. According to the Chinese National Standards of GB 3838-2002 and GB 18918-2002, the comprehensive water quality in Haihe River Basin has been described. Results showed that the comprehensive water quality in 6 sites, 4 sites, and 20 sites were good, bad, and medium. Furthermore, 162 dominant bacterial species were identified in surface and subsurface sediments in the 30 sampling sites. As revealed by two initial models constructed by logistic regression, the comprehensive water quality exhibited a pattern from good to bad as the ratio of the number of dominant bacterial species in surface sediments to that in subsurface sediments increased from 1 to 2.1. This finding possibly bridged a traditional gap between aquatic microbe indicators and water quality assessment or monitoring techniques.

Controlling the simultaneous production of laccase and lignin peroxidase from Streptomyces cinnamomensis by medium formulation.

BACKGROUND: Use of crude ligninase of bacterial origin is one of the most promising ways to improve the practical biodegradation of lignocellulosic biomass. However, lignin is composed of diverse monolignols with different abundance levels in different plant biomass and requires different proportions of ligninase to realize efficient degradation. To improve activity and reduce cost, the simultaneous submerged fermentation of laccase and lignin peroxidase (LiP) from a new bacterial strain, Streptomyces cinnamomensis, was studied by adopting formulation design, principal component analysis, regression analysis and unconstrained mathematical programming. RESULTS: The activities of laccase and LiP from S. cinnamomensis cultured with the optimal medium formulations were improved to be five to eight folders of their initial activities, and the measured laccase:LiP activity ratios reached 0.1, 0.4 and 1.7 when cultured on medium with formulations designed to produce laccase:LiP complexes with theoretical laccase:LiP activity ratios of 0.05 to 0.1, 0.5 to 1 and 1.1 to 2. CONCLUSION: Both the laccase and LiP activities and also the activity ratio of laccase to LiP could be controlled by the medium formulation as designed. Using a crude laccase-LiP complex with a specially designed laccase:LiP activity ratio has the potential to improve the degradation of various plant lignins composed of diverse monolignols with different abundance levels.

Biosorption of aquatic cadmium(II) by unmodified rice straw.

Cadmium is the most common toxic metal threatening safe rice supply. Rice straw has the potential to remove Cd from large-scale effluent contaminated by heavy metals since it exhibited a short biosorption equilibrium time of 5 min, high biosorption capacity (13.9 mg g(-1)) and high removal efficiency at a pH range of 2.0-6.0. The main Cd biosorption mechanism was Cd(2+) ion exchange with K(+), Na(+), Mg(2+) and Ca(2+), together with chelation with functional groups such as C=C, CO, OH and carboxylic acids. When 0.5% (w/v) rice straw was exposed to 50 mg mL(-1) CdSO(4) solution with shaking at 150 r min(-1) for 3h, about 80% of the aquatic Cd was absorbed and the Cd content in rice straw reached 8-10 mg g(-1), suggesting that the metal-enriched rice straw could become high quality bio-ore by virtue of the industrial mining grade of its metal content and easy metal recovery.

Improving the simultaneous production of laccase and lignin peroxidase from Streptomyces lavendulae by medium optimization.

To improve laccase (Lac) and lignin peroxidase (LiP) production from Streptomyces lavendulae, the Lac and LiP activity models were constructed and the C-N sources formulation in the medium optimal for the simultaneous production of Lac-LiP complex was asparagine 16.44%, urea 23.48%, fructose 18.01%, malt extract 21.21%, (NH(4))(2)SO(4) 20.86%. By nutritional analysis, the optimal initial mole ratio of C/N for laccase and LiP production were 1.48, 1.43 with C, N levels of 1.298-1.308 mol L(-1) and 0.875-0.912 mol L(-1), respectively. Verification experiment revealed that the initial C/N ratio in medium was the key factor affecting laccase activity, and the combined C, N sources could improve ligninolytic enzymes activity. Thus, enzyme production cost could be cut down effectively, not only by the simultaneous fermentation of Lac-LiP complex, but also by maintaining the initial C/N mole ratio at 1.43-1.48 in the medium with low levels, and different kinds of C and N sources.

Optimization of laccase production from Trametes versicolor by solid fermentation.

The regulation of culture conditions, especially the optimization of substrate constituents, is crucial for laccase production by solid fermentation. To develop an inexpensive optimized substrate formulation to produce high-activity laccase, a uniform design formulation experiment was devised. The solid fermentation of Trametes versicolor was performed with natural aeration, natural substrate pH (about 6.5), environmental humidity of 60% and two different temperature stages (at 37 degrees C for 3 days, and then at 30 degrees C for the next 17 days). From the experiment, a regression equation for laccase activity, in the form of a second-degree polynomial model, was constructed using multivariate regression analysis and solved with unconstrained optimization programming. The optimized substrate formulation for laccase production was then calculated. Tween 80 was found to have a negative effect on laccase production in solid fermentation; the optimized solid substrate formulation was 10.8% glucose, 27.7% wheat bran, 9.0% (NH4)2SO4, and 52.5% water. In a scaled-up verification of solid fermentation at a 10 kg scale, laccase activity from T. versicolor in the optimized substrate formulation reached 110.9 IU/g of dry mass.

Optimization of cellulase complex formulation for peashrub biomass hydrolysis.

To improve efficiency and reduce cost, solid state simultaneous saccharification and fermentation of peashrub woody biomass was investigated under anaerobic conditions at 50 degrees C, with a cellulase-inoculant mixture consisting of Trichoderma koningii cellulase, Aspergillus niger cellulase, and Lactobacillus. Experimental formulations were prepared according to uniform prescription design principles. By crude protein, crude fiber models constructed using multivariate regression in SPSS and solutions analysis through unconstrained mathematical optimization in Microsoft Excel, it was clearly revealed that low pH value (3.8) from lactic acid accumulation produced by Lactobacillus would ultimately limit enzymatic hydrolysis during long-term fermentation (30 days). It was shown that a cellulase complex with filter paper cellulase/carboxymethyl cellulase/cotton lyase/beta-glucosidase/pectinase of activity ratios of 0.6:1:0.3:1:2.6 could effectively break peashrub cell wall structure by biodegradation of easily digested components and, then, release cellular contents to improve crude protein content. Thus, the enzymatic hydrolysis of peashrub biomass by the optimized cellulase complex could improve crude protein content by 45.3% (from 8.45 to 12.28%), although it only biodegraded about 10.90% of the crude fiber (from 44.45 to 40.08%).

Optimization of solid fermentation of cellulase from Trichoderma koningii.

To exploit peashrub resources in Ordos as fodders, it is very crucial to realize industrial production of cheap cellulase of high activity by optimizing culture technology, especially culture substrate. In this study, a new prescription experiment based on uniform design ideal was invented and successfully applied in the solid fermentation of Trichoderma koningii F244, which was performed with two different temperature degrees. The activities of FPA, cotton lyase, CMCase and beta-glucosidase were assayed and then mathematical models of enzymatic activities, which were figured out by Unconstraint Mathematical Programming, were developed by Multivariate Regression Program of SPSS10.0. Enzymatic activities of optimized substrate prescriptions corresponding to mathematical models were forecasted to determine an ideal substrate prescription. It is revealed that in solid fermentation, Tween80 has negative effect on cellulase production. Furthermore, the ideal prescription for cellulase complex production by Trichoderma koningii F244 was straw powder 16.9%, wheat bran 26.5%, (NH4)2SO4 9.5% and water 47.1%, whose corresponding cellulase activity was expected to be at the same high level with that of Trichoderma reesei Q9414 on its own recommended substrate. Especially, goats mainly fed on peashrub tissues mixed with cellulase complex of this prescription and culture technology, got an incremental ratio of 0.3 kg/d, which brought a very promising feeding prospect for local peashrub resource. By populization of this cellulase complex, it can integrate living standard, economic construction of local residents into vegetational restoration tightly and thus this paper will be very meaningful to be use for reference for western China like Ordos to realize its sustainable development of economy, society and environment.