Optical biosensor technology continues to be the method of choice for label-free, real-time interaction analysis. But when it comes to improving the quality of the biosensor literature, education should be fundamental. Of the 1413 articles published in 2008, less than 30% would pass the requirements for high-school chemistry. To teach by example, we spotlight 10 papers that illustrate how to implement the technology properly. Then we grade every paper published in 2008 on a scale from A to F and outline what features make a biosensor article fabulous, middling or abysmal. To help improve the quality of published data, we focus on a few experimental, analysis and presentation mistakes that are alarmingly common. With the literature as a guide, we want to ensure that no user is left behind.

Grading the commercial optical biosensor literature-Class of 2008: 'The Mighty Binders'.

High concentration ethanol production from corncob residues by fed-batch strategy.

This study investigated the development of fungal community composition in arable soil during the degradation of straw residue. We explored the short-term responses of the fungal community over 28 days of decomposition in soil using culture-independent polymerase chain reaction in combination with a clone library and denaturing gradient gel electrophoresis (DGGE). Fungal cellobiohydrolase I (cbhI) genes in the soil were also characterized, and their diversity suggested the existence of a different cellulose decomposer. The DGGE profiles based on fungal internal transcribed spacer analysis showed different successions of fungal populations during residue decomposition. Members of Lecythophora and Sordariales were dominant in the early succession, while Hypocrea and Engyodontium were better adapted in the late succession. The succession of fungal communities might be related to changes of residue quality during decomposition. Collectively, sequences assigned to Ascomycota members were dominant at different stages of the fungal succession during decomposition, revealing that they were key drivers responsible for residue degradation in the arable soil tested.

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Ascomycota members dominate fungal communities during straw residue decomposition in arable soil.

Despite intensive research, the mechanism of the rapid retardation in the rates of cellobiohydrolase (CBH) catalyzed cellulose hydrolysis is still not clear. Interpretation of the hydrolysis data has been complicated by the inability to measure the catalytic constants for CBH-s acting on cellulose. We developed a method for measuring the observed catalytic constant (k(obs)) for CBH catalyzed cellulose hydrolysis. It relies on in situ measurement of the concentration of CBH with the active site occupied by the cellulose chain. For that we followed the specific inhibition of the hydrolysis of para-nitrophenyl-beta-D-lactoside by cellulose. The method was applied to CBH-s TrCel7A from Trichoderma reesei and PcCel7D from Phanerochaete chrysosporium and their isolated catalytic domains. Bacterial microcrystalline cellulose, Avicel, amorphous cellulose, and lignocellulose were used as substrates. A rapid decrease of k(obs) in time was observed on all substrates. The k(obs) values for PcCel7D were about 1.5 times higher than those for TrCel7A. In case of both TrCel7A and PcCel7D, the k(obs) values for catalytic domains were similar to those for intact enzymes. A model where CBH action is limited by the average length of obstacle-free way on cellulose chain is proposed. Once formed, productive CBH-cellulose complex proceeds with a constant rate determined by the true catalytic constant. After encountering an obstacle CBH will "get stuck" and the rate of further cellulose hydrolysis will be governed by the dissociation rate constant (k(off)), which is low for processive CBH-s.

Mechanism of initial rapid rate retardation in cellobiohydrolase catalyzed cellulose hydrolysis.

Does change in accessibility with conversion depend on both the substrate and pretreatment technology

The enzymatic hydrolysis rate of cellulose decreases with irreversible adsorption of cellobiohydrolase I

The invention discloses an effective microbiological detection method capable of being applied to oil-gas exploration, belongs to the field of biotechnology, and relates to a method for detecting unusual methane-oxidizing bacteria content, which can be applied to microbial oil-gas exploration, takes methane-oxidizing bacteria as indicators and can effectively avoid the influence of biomethanation. The methane-oxidizing bacteria and methanogens in a soil sample are respectively quantified by a Real-time polymerase chain reaction (PCR) technology, the methane-oxidizing bacteria content and ratios of the methane-oxidizing bacteria to the methanogens in different regions are compared, and that whether the reason of unusual methane-oxidizing bacteria is biomethanation is further deduced, so that the influence of the biomethanation is eliminated and risks of false negative results are reduced. The method can be applied to the microbial oil-gas exploration, provides cheap and effective help for the early stage of the exploration, and indicates and predicts favorable exploration blocks to reduce exploration risks and cost.

Effective microbiological detection method capable of being applied to oil-gas exploration

The invention relates to a method for recycling production of a paenibacillus polymyxa microbial agent from citric acid wastewater, and belongs to the technical field of microbial agents and wastewater recycling. The method adopts main medium raw materials of high-concentration organic wastewater produced in citric acid production and utilizes a liquid-state fermentation method to produce the paenibacillus polymyxa microbial agent. The method comprises the following steps of 1, carrying out pH value adjustment and sterilization of citric acid wastewater, 2, inoculating a triangular flask with paenibacillus polymyxa subjected to slant preservation, and carrying out shaking culture to obtain a liquid strain, 3, inoculating a fermentation tank containing a citric acid wastewater medium with the liquid strain, and carrying out aseptic air culture to obtain liquid fermentation products, and 4, mixing the liquid fermentation products and bio-activated carbon to obtain the paenibacillus polymyxa microbial agent which is solid. The paenibacillus polymyxa microbial agent obtained by the method has the characteristics of low production cost and good environmental benefits, can obviously improves soil environment quality, a crop yield and crop quality, and can control a plurality of diseases of plants. The method provides an approach for effective recycling utilization of a mass of high-concentration wastewater produced in citric acid production, and reduces pollutant discharge.

Method for recycling production of paenibacillus polymyxa microbial agent from citric acid wastewater

Microbial communities of different depths (30, 60, 100, 150, 200cm) from the unexploited oilfield, gas field and control area were studied by PCR-DGGE and sequencing methods. The objectives of this study were to understand the microbial distribution in the regions of unexploited oil and gas fields, and to investigate the potential microbial indicators of oil and gas resources. The results showed that the Dice coefficients between different depths were very low (26-69.9). The microbial communities in the soil of 150 cm and 200 cm depth had greater richness (S > or = 19), diversity (H > or = 2.69) and evenness (E > or = 0. 90). The results of sequencing demonstrated that the bands from oilfield were mainly grouped into alpha-Proteobacteria, gamma-Proteobacteria, Actinobacteria, Acidobacteria with the predominance of gamma-Proteobacteria (75%). Most of the bands were related to oil-associated and hydrocarbon degrading bacteria, such as Methylophaga and Alcanivorax. While the gas field had alpha, beta, gamma, delta-Proteobacteria and Bacteroidetes, and gamma-Proteobacteria accounted for only 24%. More strains showed relativity to methanotrophs, such as Methylocystaceae. Thus, 150 cm and 200 cm were more suitable as the oil-gas exploration sampling depth. Methylocystaceae may act as potential indicators for gas resources, Methylophaga and Alcanivorax for oil.

Anzhou Ma

Papers

The enzymatic hydrolysis rate of cellulose decreases with irreversible adsorption of cellobiohydrolase I

Effective microbiological detection method capable of being applied to oil-gas exploration

Method for recycling production of paenibacillus polymyxa microbial agent from citric acid wastewater

[Microbial community structure analysis of unexploited oil and gas fields by PCR-DGGE].

Method for preparing 13C stable isotope labeled cellulose