A strain of the cyanobacterium Arthrospira was isolated from Lake Chahannaoer in northern China and was characterized according to microscopic morphology, photosynthetic oxygen-evolving activity, growth rate, and nutritional profile. Compared with thermophilic Arthrospira species occurring naturally in tropical and subtropical lakes, this isolate is mesophilic and grows optimally at 20 o C. The total protein, fatty acid, phycocyanin, carotenoid, and chlorophyll a contents were 67.6, 6.1, 4.32, 0.29, and 0.76 grams per 100 grams of dry weight, respectively. The strain is rich in polyunsaturated fatty acids (PUFAs). An essential omega-3 fatty acid, docosahexaenoic acid (DHA), was detected, and γ-linolenic acid (GLA) and DHA accounted for 28.3% of the total fatty acid content. These features of this newly isolated strain make it potentially useful in commercial mass culture in local areas or as a biofuel feedstock. It is also an alternative resource for studying the metabolic PUFA pathways and mechanisms of cold stress tolerance in cyanobacteria.

Lactose intolerance is an important factor restricting the consumption of dairy products. Lactase is used to hydrolyze lactose in milk while generating galactooligosaccharides (GOS), thereby reducing the incidence of lactose intolerance. We used cow milk as raw materials, and selected enzyme preparations with high lactose hydrolysis rate and strong GOS generation ability from 14 commercially available lactase enzymes. The lactose hydrolysis rate is 5.85%-81.38%, and the GOS content is 0.03 g/L- 13.10 g/L. The mixing experiment design determined the two lactase enzymes (E10 and E11) ratio and the optimal enzymatic hydrolysis process of low-lactose prebiotic milk: compound lactases (E10:E11=0.756:0.244) addition 0.11%, 55℃for 5h, lactose hydrolysis rate and GOS content were 98.02% and 19.69g/L, respectively, and the remaining lactose content was about 0.97 g/L.

The effect of sodium tripolyphosphate, glycerol, vitamin B2, mannitol and solid malt extract on the freeze-dried powder survival rate and the viable cells of the B. bifidum BB01 were studied by single-factor test in this study. The optimal concentration of protectant for B. bifidum during freeze-drying were 1.5% (W/V) sodium tripolyphosphate, 12% (W/V) glycerol, 6% (W/V) vitamin B2, 6% (W/V) mannitol and 6% (W/V) solid malt extract, and the survival rate of bacteria was 18.63%, 22.98%, 24.13%, 24.19% and 39.77%, respectively.

Waste recycling is beneficial not only for the environment but also for the economy and the society at large. Corn stalks, the most abundant crop waste, are processed with oven drying, steaming, complex enzymatic hydrolysis (cellulase, xylanase, β-glucanase and pectinase), and fermentation (by Candida utilis and Pachysolen tannophilus), were analyzed via X-ray diffraction, Scanning Electron Microscopy (SEM) and Infrared Spectroscopy (IR). The results indicated that thermophilic digestion destroyed glycosidic bonds and fibrous crystal have a significant effect on the degradation of the corn stalks, while complex enzyme hydrolysis only slightly degraded fibrous crystal. Fermentation did not significantly reduce fibrous crystal. Therefore, our research suggested that thermophilic digestion is the appropriate way to increase the saccharification rate and feed yield of corn stalks.