Effect of galangal essential oils on rumen microbial population and biodiversity on in vitro rumen fermentation

Abstract

The study aimed to evaluate the effect of administering galangal essential oil (EO) on the abundance of rumen bacteria using the 16s rRNA method. The treatments included a control (no EO addition), galangal EO (30, 60, 120 µL), and cineole (5 µL). The treatments were assessed using a 48‐hour in vitro batch culture of rumen fluid containing a 60:40 ratio of forage to concentrate. For amplification of the prokaryotes (bacteria and archaea) in region V4, 16s rRNA primer 5’GTGCCAGCMGCCGCGTAA, GGACTACHVGGGTWTCTAAT3’ was employed. The data for rumen microbial abundance were analysed descriptively, while the data for rumen microbial diversity were obtained from the report on the Next Generation Sequencing Method. The microbial composition of each sample was tested for operational taxonomic units (OTUs) with a 97% identity rate on a valid label. The 16S rRNA gene sequencing yielded a total of 3,977 OTUs. Adding galangal and cineole EOs resulted in the same variation of the Shannon index. The population index (chao1 index) was highest when 60 µL of galangal EO was added, compared to 30 and 120 µL of galangal EO and cineole. In addition, providing 60 µL of galangal EO decreased the abundance of Prevotella ruminicola compared to the control and cineole doses. The addition of galangal EO also led to a decline in the number of Methanobacteriales. The population of the fibre‐degrading bacteria group (Ruminococcus albus and Ruminococcus flavefaciens) was higher in a dose of galangal EO than the control and cineole. Therefore, it can be concluded that the effective dose of galangal EO, i.e. 60 µL/300 mg (DM feed) in vitro, can reduce the abundance of Prevotella bacteria and methanogens.

Evaluation of lemon peel essential oil on fecal microbial diversity of tropical Holstein dairy cows

“…Hassan et al (2020) and Tekippe et al (2013) reported that adding essential oils altered rumen fermentation and increased nutrition in tropical Holstein dairy cows. Using essential oils derived from tropical plants such as galangal, ginger, eucalyptus, clove, pine, cumin and nutmeg has been shown to change rumen fermentation by reducing protein digestibility in the rumen and methane production in vitro (Liu et al, 2017;Mao et al, 2019;Benetel et al, 2022;Daning et al, 2022a). These results can be used as a basis for using essential oils as a feed additive for tropical Holstein dairy cows to increase the production and composition of tropical Holstein dairy cows' milk.…”

Metagenomic analysis of the microbial community in kefir grains from different milk sources

“…Previous investigations showed that many factors, such as the type of milk and environment, highly influence the structure and diversity of microflora in kefir grain (Schwan et al 2016). Milk sources affected microbial diversity after that described metagenomic tools already used to identify microbial diversity in kefir or other sources such as rumen (Daning et al 2022).…”