Influence of Lactic Acid on Cell Cycle Progressions in Lactobacillus bulgaricus During Batch Culture

Effects of supplemental feeding of Chinese herbal mixtures to perinatal sows on antioxidant capacity and gut microbiota of sows and their offspring piglets

The stress response of pig herds poses a significant challenge in the pig breeding industry, and investigating strategies to mitigate this stress is of paramount importance. The objective of this study was to investigate the impacts of supplemental feeding of Chinese herbal mixtures to perinatal sows on antioxidant capacity and gut microbiota of sows and their offspring piglets. A total of 60 healthy sows (Large white) at fourth parity were randomly assigned to five treatment groups. The control group received a basal diet, while the TRT1 group received a basal diet supplemented with 2kg/t Bazhen powder (BZP). The TRT2, TRT3, and TRT4 groups were fed a basal diet supplemented with 1kg/t, 2kg/t, and 3kg/t Qi-Zhu- Gui-Shao soothing liver and replenishing blood powder (QZGSP), respectively. The trial lasted for 5weeks, starting from day 100 of gestation until day 21 of delivery. The results demonstrated that the inclusion of 2kg/t and 3kg/t QZGSP significantly enhanced the antioxidant capacity of sows and their offspring piglets to different degrees, thereby effectively alleviating oxidative stress. Analysis of gut microbiota revealed that QZGSP influenced the composition of gut microbiota in both sows and their offspring piglets. Specifically, at the genus level, the abundance of Christensenellaceae_R-7_group in the gut microbiota of sows in the TRT4 group was significantly lower than that in the TRT1 group (p < 0.05), while the relative abundance of Lactobacillus in the gut microbiota of sows in the TRT4 group was significantly higher than that in the CON group (p < 0.05). Furthermore, at the genus level, compared to those in the TRT1 group, piglets from the TRT4 group exhibited a significant decrease in relative abundance of Escherichia-Shigella, Parabacteroides, and Methanobrevivacter (p < 0.05), but a significant increase in Phascolarctobacterium (p < 0.05). Spearman correlation analysis indicated a positive correlation between relative abundance of Christensenellaceae_R-7_group and serum contents of T-AOC and CAT (p < 0.05), as well as a negative correlation with serum concentration MDA (p < 0.05). Additionally, there was a positive correlation between relative abundance Lactobacillus and serum levels SOD (p < 0.01) and GSH-Px (p < 0.05). Therefore, supplementation of 3kg/t QZGSP in the periparturient sow diet significantly augmented antioxidant capacity in both sows and offspring piglets, while concurrently modulating the composition and structure of their intestinal microflora. The findings from this study demonstrate that QZGSP represents a beneficial feed additive for perinatal sows.

Differential Amino Acid Uptake and Depletion in Mono-Cultures and Co-Cultures of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus in a Novel Semi-Synthetic Medium

The mechanistic understanding of the physiology and interactions of microorganisms in starter cultures is critical for the targeted improvement of fermented milk products, such as yogurt, which is produced by Streptococcus thermophilus in co-culture with Lactobacillus delbrueckii subsp. bulgaricus. However, the use of complex growth media or milk is a major challenge for quantifying metabolite production, consumption, and exchange in co-cultures. This study developed a synthetic medium that enables the establishment of defined culturing conditions and the application of flow cytometry for measuring species-specific biomass values. Time courses of amino acid concentrations in mono-cultures and co-cultures of L. bulgaricus ATCC BAA-365 with the proteinase-deficient S. thermophilus LMG 18311 and with a proteinase-positive S. thermophilus strain were determined. The analysis revealed that amino acid release rates in co-culture were not equivalent to the sum of amino acid release rates in mono-cultures. Data-driven and pH-dependent amino acid release models were developed and applied for comparison. Histidine displayed higher concentrations in co-cultures, whereas isoleucine and arginine were depleted. Amino acid measurements in co-cultures also confirmed that some amino acids, such as lysine, are produced and then consumed, thus being suitable candidates to investigate the inter-species interactions in the co-culture and contribute to the required knowledge for targeted shaping of yogurt qualities.

Effects of dietary supplement with a Chinese herbal mixture on growth performance, antioxidant capacity, and gut microbiota in weaned pigs

Weaning stress decreases the growth performance of piglets and is one of the main concerns of pig industries. Traditional Chinese herbal medicines have been used to reduce the adverse effects of weaning stress as both nutritional supplements and antibiotic substitutes. This study aimed to evaluate the effects of a Chinese herbal mixture (Kangtaile, which contained Paeonia lactiflora, licorice, dandelion, and tea polyphenols) on the growth performances, immune response, antioxidant capacity, and intestinal microbiota of weaned pigs. A total of 400 weaned pigs [Duroc × (Landrace × Yorkshire)] were randomly allocated into one of four treatments: the CON group, fed with basic diet; the HM1 group, fed with basal diet supplemented with 0.5 g herbal mixture/kg diet; the HM2 group, fed with basal diet supplemented with 1.0 g herbal mixture/kg diet; or the HM3 group, fed with basal diet supplemented with 1.5 g herbal mixture/kg diet. The results revealed that dietary supplementation with the herbal mixture for 28 days improved average daily gain and feed conversion ratio, while decreased the diarrhea rate of weaned pigs. Moreover, dietary supple-mentation with the herbal mixture improved the antioxidant capacity through increasing the activity of catalase (CAT) and the total antioxidant capacity (T-AOC) level, while decreasing the concentration of malondialdehyde (MDA) in the serum. Pigs supplemented with herbal mixture presented an increased serum immunoglobulin (Ig)M level on day 14 compared with control pigs. The herbal mixture altered the composition of intestinal microbiota by influencing the relative abundances of Firmicutes and Bacteroidetes at the phylum level. The relative abundances of the Firmicutes and Bacteroidetes were significantly related to the body weight gain of pigs. In conclusion, supplementation of herbal mixture to the diet improved growth performance, immunity, and antioxidant capacity and modified the composition of intestinal microbiota in weaning pigs. This study provided new insights into the nutritional regulation effects of the herbal mixtures on weaned pigs.

Alternative Seamless Cloning Strategies in Fusing Gene Fragments Based on Overlap-PCR

Gene fragment swapping and site-directed mutagenesis are commonly required in dissecting functions of gene domains. While there are many approaches for seamless fusion of different gene fragments, new methods are yet to be developed to offer higher efficiency, better simplicity, and more affordability. In this study, we showed that in most cases overlap-PCR was highly effective in creating site-directed mutagenesis, gene fragment deletion, and substitutions using RUS1 and RUS2 as example. While for cases where the overlap-PCR approach is not feasible due to complex secondary structure of gene fragments, a unique restriction site can be generated at the overlapped region of the primers through synonymous mutations. Then different gene fragments can be seamlessly fused through traditional restriction digestion and subsequent ligation. In conclusion, while the classical overlap-PCR is not feasible, the modified overlap-PCR approaches can provide effective and alternative ways to seamlessly fuse different gene fragments.