In this paper, a rapid and reliable gene-targeted species-specific polymerase chain reaction (PCR) technique based on a two-step process was established to identify bifidobacteria in dairy products. The first step was the PCR assay for genus Bifidobacterium with genus specific primers followed by the second step, which identified the species level with species-specific primer mixtures. Ten specific primer pairs, designed from nucleotide sequences of the 16-23S rRNA region, were developed for the Bifidobacterium species including B.

Because of the possibility of harmful formaldehyde emissions from industrial-produced wood composites, the influence of temperature, relative humidity, and frequency of ventilation on formaldehyde emission from particleboard, plywood and fiberboard respectively, were investigated in this article. An improved generally applicable model for calculating the formaldehyde emission from wood composites was established by using the iteration method, a double exponential attenuation model, and mass transfer theory. The model parameters for the emission of formaldehyde from wood composites are also discussed in this article. It is concluded that a high-temperature or high-humidity environment will promote the emission of formaldehyde from wood composites. The process of emission of formaldehyde from wood composites can be divided into quick-release, slow-release, and release saturation phases. The formaldehyde concentration can be predicted from the formaldehyde mathematical model, and the maximum difference between observed and predicted formaldehyde concentrations is less than 15 percent under different general environmental conditions.

Mixed strains were used to increase the hydrolysis degree of materials during fermenting. Tilapia scraps and soybean meal were mixed by 1:1 and Bacillus subtilis, yeast and lactic acid bacteria were added. The optimal quantity of strains was determined by hydrolysis degree through single factor experiments and orthogonal experiments. After all, The molecular weight distribution of raw material and products was analyzed by high performance size exclusion chromatography (HPSEC). The results showed that the optimum conditions were as follows: the inoculation amount of Bacillus subtilis, the yeast and the lactic acid bacteria was 0.6‰, 0.06‰ and 0.0015‰, respectively. And the hydrolysis degree of materials increased from 10.3% to 27.3%. The hydrolysis degree of materials increased markedly by adding mixed strains.

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