Computational estimation of sediment symbiotic bacterial structures of seagrasses overgrowing downstream of onshore aquaculture.

Coastal seagrass meadows are essential in blue carbon and aquatic ecosystem services. However, this ecosystem has suffered severe eutrophication and destruction due to the expansion of aquaculture. Therefore, methods for the flourishing of seagrass are still being explored. Here, data from 49 public coastal surveys on the distribution of seagrass and seaweed around the onshore aquaculture facilities are revalidated, and an exceptional area where the seagrass Zostera marina thrives was found near the shore downstream of the onshore aquaculture facility. To evaluate the characteristics of the sediment for growing seagrass, physicochemical properties and bacterial ecological evaluations of the sediment were conducted. Evaluation of chemical properties in seagrass sediments confirmed a significant increase in total carbon and a decrease in zinc content. Association analysis and linear discriminant analysis refined bacterial candidates specified in seagrass overgrown- and nonovergrown-sediment. Energy landscape analysis indicated that the symbiotic bacterial groups of seagrass sediment were strongly affected by the distance close to the seagrass-growing aquaculture facility despite their bacterial population appearing to fluctuate seasonally. The bacterial population there showed an apparent decrease in the pathogen candidates belonging to the order Flavobacteriales. Moreover, structure equation modeling and a linear non-Gaussian acyclic model based on the machine learning data estimated an optimal sediment symbiotic bacterial group candidate for seagrass growth as follows: the Lachnospiraceae and Ruminococcaceae families as gut-inhabitant bacteria, Rhodobacteraceae as photosynthetic bacteria, and Desulfobulbaceae as cable bacteria modulating oxygen or nitrate reduction and oxidation of sulfide. These observations confer a novel perspective on the sediment symbiotic bacterial structures critical for blue carbon and low-pathogenic marine ecosystems in aquaculture.

Development of a novel feeding method for Japanese black calves with thermophile probiotics at postweaning.

AIMS: Probiotic effects of compost containing thermophiles on productivity have been reported in domestic animals, although not cattle. We evaluated the effects of administering Caldibacillus hisashii, a thermophile contained in compost, on growth, blood components, faecal organic acid concentrations and microbiota population in Japanese black calves. METHODS AND RESULTS: Calves were administered C. hisashii from 3 to 5 months of age. Administering C. hisashii decreased feed intake without affecting body weight, indicating that feed efficiency is improved by administration. Administering C. hisashii decreased plasma insulin concentration without affecting glucose and non-esterified fatty acid concentrations. Chao1 was decreased by exposure at 5 months of age. Similarly, weighted and unweighted UniFrac distances were affected by treatment at 5 months of age. Faecal abundance of the phylum Bacteroidetes tended to be increased by exposure. Faecal propionic acid concentration was correlated positively with faecal abundance of phylum Bacteroidetes but negatively with that of Firmicutes. Interestingly, the population of the genus Methanobrevibacter, representing the majority of methanogens, was lowered by exposure and was negatively correlated with faecal propionic acid concentration. CONCLUSION: Administration of C. hisashii has the potential to improve growth performance of Japanese black calves and to contribute to reducing environmental load, which may be associated with altered endocrine kinetics and gut microbial populations. SIGNIFICANCE AND IMPACT OF THE STUDY: This study revealed that isolated thermophiles included in compost may exert probiotic effects on calves.

Thermophile-fermented compost extract as a possible feed additive to enhance fecundity in the laying hen and pig: Modulation of gut metabolism.

Recently, we reported that the oral administration of an extract of compost fermented with marine animal resources and thermophilic Bacillus species should confer health benefits in fish, pigs and rodents. Herein, the relations between fecundity and gut metabolites in laying hens and pigs on farms after oral exposure to compost were investigated. On the hen farms, the egg production of hens continuously administered the extract was maintained at significantly higher levels compared with the hens not administered the extract. On the swine farms, after the compost treatment, the shipping dates of fattening pigs were shortened, with an improvement in the death rate of the pigs. When the levels of fecal organic acids, such as short-chain fatty acids, lactate, and ammonium, as indicators of gut metabolism and energy sources for peripheral tissues, were examined, the levels of the acetate, propionate, and butyrate in the feces of the hens and pigs in the compost-treated group were not always different from those in the untreated control group. However, the levels of lactate were consistently low in the feces of both animals after the compost treatment. The fecal ammonium concentrations in old hens (age 597-672 days) and 2-month-old piglets from the compost-fed mother sows were low when compared with the untreated groups. The concentrations of free organic acids and their related compounds in the animal products (eggs and pig loins) were nearly equal to those in the untreated control products. Thus, the oral administration of the thermophile-fermented compost should improve the fecundity of hens and pigs by modifying their gut metabolism.

The oral administration of thermophile-fermented compost extract and its influence on stillbirths and growth rate of pre-weaning piglets.

Food produced via fermentation with mesophilic bacteria has been used to confer health benefits. In contrast, mammalian physiological responses to the intake of thermophile-fermented products have not been thoroughly investigated. We examined the effects of administering a compost extract consisting of fermented marine animals with thermophiles, including Bacillaceae, to pregnant sows and piglets. Retrospective studies were performed on two different swine farms (n=330-1050 sows). The rate of stillbirth was markedly lower in all parities of the compost extract-fed group compared to those of the control group (p≦0.001). Additionally, the birth to weaning period of newborns was significantly shorter (p<0.0001), while the ratio of weanlings per liveborn piglets was increased by more than 6.5% in the compost extract-fed group. Thus thermophiles and their products in the compost extract might promote growth and reduce stillbirths of piglets during the birth to weaning period.