Evolutionary adaptation in the laboratory and the process of retrograde engineering augment autotrophic proliferation in Saccharomyces cerevisiae

The distribution of rennet activity between the cheese aging process and whey is not influenced by the association of enzymes with caseins

The division of rennet in cheesemaking is split between the curd and whey, influencing the taste and texture of aged cheeses. Our study aimed to examine how raising the protein concentration in reconstituted skim milk (up to 8.8 %) affects the distribution of calf rennet activity (RA) in rennet curds produced through two methods: renting only and renneting with glucono-δ-lactone (GDL) to achieve slow acidification. The distribution of rennet activity (RA) into curds increased as the concentration of skim milk rose, ranging from 8.6 % to 29.1 % without acidification, and from 6.5 % to 19.4 % when combined with slow acidification. This increase seemed to be related to the retention of moisture and protein. Surprisingly, the concentration of residual RA in the whey (measured in international milk clotting units, IMCU/mL) remained unaffected and remained consistent with the initial IMCU/mL of milk. This suggests that the division of RA between curd and whey is not influenced by the association of enzymes with caseins (CNs). Instead, it is possible that the strength of interactions between CNs themselves plays a significant role. These findings could be valuable for research focused on enhancing the cheese aging process.

Effects of duo-strain probiotics on growth, digestion, and gut health in broiler chickens

The goal of this inquiry was to analyze the impact of incorporating Enterococcus faecium and Streptococcus thermophilus using a novel premix-spray method on the following aspects: growth rate, digestive enzyme activity, antioxidant levels, gut microbiome composition, and the morphological characteristics of the duodenum, jejunum, and ileum in broiler chickens. Furthermore, this study explored the potential benefits of duo strains of probiotics (DSP) in reducing flatulence, regulating stool microbial population, and improving diarrhea symptoms. A total of 360 one-day-old mixed-sex Plymouth Rock chicks (IW: 51 ± 33 g) were randomly divided into two treatment groups. Each treatment group was further divided into 9 replicated cages, with 20 chicks housed in each cage. The control group (CG) received a basal diet composed of a soy-corn mixture, whereas the experimental group was provided with DSP (CON + 0.5 % probiotic). The results showed that the increase in the body weight of broilers at the end of the fourth week in the control group and the treatment group was 1.576 versus 1.847 kg, respectively. Throughout the 30-day trial period, the DSP diet significantly improved the specific growth rate (SGR), survival rate (SR), and body weight gain (BWG) while decreasing the feed conversion ratio (FCR) (P < 0.05). The DSP diet also enhanced the Enzymatic digestion (protease, amylase, lipase, and trypsin) and antioxidant potential (SOD, MDA, and catalase) of the broilers compared to those in the CG. The results revealed significant enhancements in the tissue morphology of the duodenum and jejunum following the combined treatment for a duration of 4 weeks. The DSP treatments significantly increased microvillus height in the duodenum and jejunum but had no notable effects in the ileum. Incorporating 0.5 % DSP in poultry feed improved the relative abundance of Ruminococcaceae and Faecalibacteriumin, leading to better management of diarrhea and reduced presence of E. coli compared to the control diet. Additionally, including probiotics in the basal diet reduced H2S, CO2, NH3, and CH4 levels. Overall, the study suggests that the new spray-drying approach with these strains has potential for supplementing probiotics in poultry feed processing, and including DSP in broiler chicken diets has beneficial effects.