From transients to permanent residents: the existence of obligate aerobic microorganisms in the goat rumen.

The rumen serves as a complex ecosystem, harboring diverse microbial communities that play crucial ecological roles. Because previous studies have predominantly focused on anaerobic microorganisms, limited attention has been given to aerobic microorganisms in the goat rumen. This study aims to explore the diversity of aerobic microorganisms in the rumen and understand their niche and ecological roles. Rumen fluid samples were collected from 6 goats at different time points post-morning feeding. pH, NH3-N, and volatile fatty acid (TVFA) concentrations were measured, while In vitro cultivation of aerobic microorganisms was performed using PDA medium. Internal Transcribed Spacer (ITS) and 16S sequencing unveiled microbial diversity within the rumen fluid samples. Evidence of obligate aerobic microorganisms in the goat rumen suggests their potential contribution to ecological functionalities. Significantly, certain aerobic microorganisms exhibited correlations with TVFA levels, implying their involvement in TVFA metabolism. This study provides evidence of the existence and potential ecological roles of obligate aerobic microorganisms in the goat rumen. The findings underscore the significance of comprehensively deciphering goat rumen microbial communities and their interactions, with aerobes regarded as permanent residents rather than transients. These insights form a solid foundation for advancing our understanding of the intricate interplay between goat and their aerobic microorganisms in the rumen.

Differences in composition and diversity of rumen fungi in buffalo fed different diets.

The rumen is a complex ecosystem containing a variety of fungi, which are crucial for the digestive activities of ruminants. Previous research on rumen fungi has mainly focused on anaerobic fungi, given the rumen's reputation as a mainly anaerobic environment. The objective of this study was to investigate rumen fungal diversity and the presence of aerobic fungi in buffalo fed on different diets. Three adult buffaloes were used as experimental animals. Alfalfa hay, oat hay, whole corn silage, sugarcane shoot silage, fresh king grass, dried rice straw, and five kinds of mixed diets with concentrate to roughage ratios of 20:80, 35:65, 50:50, 65:35, and 80:20 were used as the experimental diets. The experimental animals were fed different diets for 22 days. Rumen fluid was collected from the rumen fistula for ITS (Internal Transcribed Spacer) sequencing 2 h after feeding on the morning of day 22. The results indicate the presence of large quantities of aerobic fungi in the rumen of the buffaloes 2 h after feeding and suggest that Ascomycota and Basidiomycota are the dominant fungal groups under different feeding conditions. The study also identified 62 different fungal types, which showed significant differences among the 11 experimental diets.

Morphological and molecular evidence of eight new species of the genus Scaptodrosophila Duda (Diptera, Drosophilidae) from China.

By integrating morphological and molecular evidences, seven new species of the Scaptodrosophila coracina species group and one new species of uncertain affinity to this genus from China are recognized and described: S. angustifolia sp. nov., S. apunctata sp. nov., S. latifoliacea sp. nov., S. longiciliata sp. nov., S. melanovittata sp. nov., S. polytricapillum sp. nov., S. undulata sp. nov. and S. curvata sp. nov. A key to the examined species is provided. Intra- and interspecific, pairwise p-distances with DNA barcodes (partial sequences of the mitochondrial COI, i.e., cytochrome c oxidase subunit I gene) are calculated and summarized. In addition, S. zebrina Liu Chen, 2018 from Yunnan, China is recognized as junior homonym of S. zebrina (Bezzi, 1928) and renamed as S. zebromyia nom. nov.