Alkaline protease production by solid state fermentation on polyurethane foam

This paper investigated the process of solid state fermentation (SSF) using PUF (polyurethane foam) as inert solid support to produce alkaline protease. Maximal enzyme activity was 2185U/ml at pH 9.0, incubation temperature 32 0C inoculum amount of 1.0 % (v/v) , nutrient solution3.75 ml/g PUF, incubation time for 2 h and 15.0 mM of added CaCl2. Under the same conditions, the yield of alkaline protease produced by SSF using PUF as support is higher than that by submerged fermentation (SMF)

Clavulanic Acid Production by Streptomyces clavuligerus using Solid State Fermentation on Polyurethane Foam

Clavulanic acid (CA), a metabolite of Streptomyces clavuligerus, is a potent β-lactamase inhibitor. In this study, polyurethane foam (PUF) was used as inert solid support to produce clavulanic acid by solid state fermentation (SSF). Maximal CA yield of 263 µg/ml was obtained at pH 6.5, incubation temperature 29°C, 10 ml medium per 3 g PUF, 0.015% added glycerol, 2% added lithium chloride (LiCl), and 2 g/L added ornithine. Under the same conditions, the yield of CA produced by SSF on PUF is apparently higher than that by submerged fermentation (SMF). In addition, CA produced by using this method is of higher purity and easier to be extracted. Citation: Wang, H. and Chen, H. (2016). Clavulanic Acid Production by Streptomyces clavuligerus using Solid State Fermentation on Polyurethane Foam. Trends in Renewable Energy, 2(1), 2-12. DOI: 10.17737/tre.2016.2.1.001

Designing forest biodiversity experiments : general considerations illustrated by a new large experiment in subtropical China

Funded by German Research Foundation. Grant Number: DFG FOR 891/1 and 2 National Natural Science Foundation of China. Grant Numbers: NSFC 30710103907, 30930005, 31170457 , 31210103910 Swiss National Science Foundation (SNSF) Sino-German Centre for Research Promotion in BeijingPeer reviewedPublisher PD

The SEPALLATA-like gene HrSEP1 in Hippophae rhamnoides regulates flower development by interacting with other MADS-box subfamily genes

MADS-box genes are classified into five categories: ABCDE, including SEP1, SEP2, SEP3, SEP4, and other homologous genes, which play important roles in floral organ development. In this study, the cDNA sequence of the HrSEP1 gene was cloned by RT-PCR and confirmed that this gene belongs to the MADS-box gene family. In addition, subcellular localization experiments showed that the HrSEP1 protein was localized in the nucleus. We verified the interaction of HrSEP1 with HrSOC1, HrSVP, and HrAP1 using yeast two-hybrid and bimolecular fluorescence complementation assays. These genes jointly regulate the growth and development of floral organs. We also found a strong synergy between HrSEP1 and AP1 genes in sepals, petals, and stamens by transgenic methods and fluorescence quantitative PCR, suggesting that HrSEP1 and AP1 may co-regulate the development of these structures. In conclusion, the expression of HrSEP1 has a certain effect on the development of floral organs, and these findings lay the foundation for further research on the biological functions of MADS transcription factors in Hippophae rhamnoides

Conformational Transition Pathway in the Inhibitor Binding Process of Human Monoacylglycerol Lipase

Human monoacylglycerol lipase (MGL) catalyzes the hydrolysis of 2-arachidonoylglycerol to arachidonic and glycerol, which plays a pivotal role in the normal biological processes of brain. Co-crystal structure of the MGL in complex with its inhibitor, compound 1, shows that the helix α4 undergoes large-scale conformational changes in response to the compound 1 binding compared to the apo MGL. However, the detailed conformational transition pathway of the helix α4 in the inhibitor binding process of MGL has remained unclear. Here, conventional molecular dynamics (MD) and nudged elastic band (NEB) simulations were performed to explore the conformational transition pathway of the helix α4. Conventional MD simulations unveiled that the compound 1 induced the closed conformation of the active site of MGL, reduced the conformational flexibility of the helix α4, and elicited the large-scale conformational rearrangement of the helix α4, leading to the complete folding of the helix α4. Moreover, NEB simulations revealed that the conformational transition pathway of helix α4 underwent an almost 180° counter-clockwise rotation of the helix α4. Our computational results advance the structural and mechanistic understanding of the inhibitory mechanism

Designing forest biodiversity experiments: general considerations illustrated by a new large experiment in subtropical China


 Biodiversity-ecosystem functioning (BEF) experiments address ecosystem-level consequences of species loss by comparing communities of high species richness with communities from which species have been gradually eliminated. BEF experiments originally started with microcosms in the laboratory and with grassland ecosystems. A new frontier in experimental BEF research is manipulating tree diversity in forest ecosystems, compelling researchers to think big and comprehensively.
 We present and discuss some of the major issues to be considered in the design of BEF experiments with trees and illustrate these with a new forest biodiversity experiment established in subtropical China (Xingangshan, Jiangxi Province) in 2009/2010. Using a pool of 40 tree species, extinction scenarios were simulated with tree richness levels of 1, 2, 4, 8 and 16 species on a total of 566 plots of 25.8 × 25.8 m each.
 The goal of this experiment is to estimate effects of tree and shrub species richness on carbon storage and soil erosion; therefore, the experiment was established on sloped terrain. The following important design choices were made: (i) establishing many small rather than fewer larger plots, (ii) using high planting density and random mixing of species rather than lower planting density and patchwise mixing of species, (iii) establishing a map of the initial 'ecoscape' to characterize site heterogeneity before the onset of biodiversity effects and (iv) manipulating tree species richness not only in random but also in trait-oriented extinction scenarios.
 Data management and analysis are particularly challenging in BEF experiments with their hierarchical designs nesting individuals within-species populations within plots within-species compositions. Statistical analysis best proceeds by partitioning these random terms into fixed-term contrasts, for example, species composition into contrasts for species richness and the presence of particular functional groups, which can then be tested against the remaining random variation among compositions.
 We conclude that forest BEF experiments provide exciting and timely research options. They especially require careful thinking to allow multiple disciplines to measure and analyse data jointly and effectively. Achieving specific research goals and synergy with previous experiments involves trade-offs between different designs and requires manifold design decisions.&#13