Isolation, identification and utilization of lactic acid bacteria from silage in a warm and humid climate area

Abstract

The study aimed to isolate and identify lactic acid bacteria (LAB) from silages and their application to improve the fermentation quality of alfalfa. Forty-nine LAB strains were isolated from silages, and two strains were screened for growth and acid production rates. Then two strains were selected for Physiological and morphological tests and 16S rRNA sequencing. They were Gram-positive and Catalase-negative and were able to grow at pH 3.5 and at 45 °C, were unable to grow different NaCl concentrations as 3.0% and 6.5%. Strain BDy3-10 was identified as Lactobacillus rhamnosus, while TSy1-3 was identified as L. buchneri. The selected strains were evaluated on fermentation of alfalfa silage. The highest crude protein content occurred in the BDy3-10 treatment group. The contents of neutral detergent fiber and acid detergent fiber in the TSy1-3 treatment were significantly lower than other treatment (P < 0.05). Compared to the control treatment, inoculation treatments deceased pH during ensiling (P < 0.001) and provided the most increased lactic acid content after ensiling for 10 days (P < 0.001). The acetic acid contents of all the inoculation groups were significantly increased (P < 0.001) during ensiling, and were lower than that of control group (P < 0.001). So, the TSy1-3 treatment most effectively improved the fermentation quality of alfalfa silage in warm and humid climate area.

Application of Lactobacillus inoculant from various rice paddy (Oryza sativa) to total mixed ration silage microbial composition

“…Homofermentatives LAB tended to be unable to maintain silage quality in aerobic conditions (Borreani et al 2018;Wilkinson and Davies 2013;Peng et al 2021). Some studies showed that although homofermentative LAB was more beneficial in anaerobic conditions, heterofermentative LAB actually increased the stability of silage quality in aerobic conditions (Muck et al 2018;Peng et al 2021). The present study proved that local LAB from local rice paddy was closest to L. plantarum's ability to encourage LAB populations in TMR silage.…”

“…According to Ellis et al (2016), the most commonly used strains of LAB were L. plantarum and other Lactobacilli, and Enterococci (E. faecium) and some Pediococci. Homofermentatives LAB tended to be unable to maintain silage quality in aerobic conditions (Borreani et al 2018;Wilkinson and Davies 2013;Peng et al 2021). Some studies showed that although homofermentative LAB was more beneficial in anaerobic conditions, heterofermentative LAB actually increased the stability of silage quality in aerobic conditions (Muck et al 2018;Peng et al 2021).…”

Effects of different additives on the bacterial community and fermentation mode of whole-plant paper mulberry silage

“…Further studies of microbial community structure and composition are necessary. Our previous study showed that L. rhamnosus produces acid and grows rapidly ( Peng et al, 2021 ). In this study, no obvious separation of LR combined with a low corn flour ratio (0, 3, and 6%) was observed, which may be due to various factors, such as the high buffer energy and low WSC content of paper mulberry ( Dong et al, 2020 ; Guo et al, 2021 ).…”

“…After all strains were isolated and purified, their acid production and growth rate in 24 h were measured on MRS medium (anaerobic at 37°C) ( Peng et al, 2021 ). Lacticaseibacillus rhamnosus (LR) strain (BDy3-10), which had the highest acid production rate, and Lentilactobacillus buchneri (LB) strain (TSy1-3), which had the fastest growth rate, were selected as the LAB additives in this study ( Peng et al, 2021 ). As shown in the strain characteristics Supplementary Table 1 , two strains were Gram-positive and Catalase-negative.…”

“…In the end, a total of 130 bacterial species were isolated, of which 49 were identified 10.3389/fmicb.2022.904193 as LAB. After all strains were isolated and purified, their acid production and growth rate in 24 h were measured on MRS medium (anaerobic at 37 • C) (Peng et al, 2021). Lacticaseibacillus rhamnosus (LR) strain (BDy3-10), which had the highest acid production rate, and Lentilactobacillus buchneri (LB) strain (TSy1-3), which had the fastest growth rate, were selected as the LAB additives in this study (Peng et al, 2021).…”