Therefore, we isolated and characterized LAB strains inhabiting vegetative forage crops, taking particular interest in the development of novel Omipalisib molecular weight inoculants contributing to good fermentation quality of paddy rice silage. Finally, we investigated differences in the fermentation quality of paddy rice silage inoculated with different conspecific strains, as well as the possibility that the isolates could aid efficient fermentation of the silage. The source of isolation was described in our previous studies (Kobayashi et al., 2010; Tohno et al., 2012a). The isolation process is
described below. Grass silage (mixed pasture of timothy grass and orchardgrass), which was stored in a round bale for 300 days, was transferred into sterile homogenization bags, suspended 1 : 10 (w/v) in sterilized distilled water, and homogenized for 1 min in a Promedia Selleckchem IWR-1 SH-II M homogenizer (ELMEX, Tokyo, Japan). Serial dilutions were used for isolation of LAB using Lactobacilli de Man Rogosa Sharpe (MRS) agar (Difco, Detroit, MI) at 30 °C for 48 h under anaerobic conditions in a TE-HER Hard Anaerobox model ANX-1 (Hirosawa
Ltd, Tokyo, Japan). Isolation and purification were as follows: colonies on MRS agar medium were picked and streaked to single colonies twice on MRS agar. The pure cultures were grown on MRS agar at 30 °C for 24 h, picked and transferred to nutrient broth (Difco) with 10% glycerol, and stored as stock cultures at −80 °C. The four isolated strains used were designated TO1000, TO1001, TO1002, and TO1003. These strains were deposited in the National Institute of Technology and Evaluation Biological Resource Center (Kisarazu, Chiba, Japan). Molecular phylogeny analysis was conducted, and a phylogenetic tree was constructed based on about 1500 bases of 16S ribosomal RNA (rRNA) gene sequence as previously described (Tohno et al., 2012b). A recA multiplex PCR assay was performed to distinguish closely related species Cell press and subspecies of the L. plantarum group according to our previous report (Tohno et al., 2012b). PCR amplification of known plantaricin genes was conducted as described
elsewhere (Omar et al., 2006). The primers used are listed in Supporting Information, Table S1. Paddy rice (Oryza sativa L. subsp. japonica) at the fully ripe stage was obtained from a local field at Kumagaya, Saitama, Japan, on October 25, 2010, by cutting using grass shears. In a small-scale fermentation system (Cai et al., 1997), approximately 100-g portions of the materials, chopped into about 20-mm lengths, were packed into 180 × 260 cm Hiryu KN-type plastic film bags (Asahikasei, Tokyo, Japan) with or without various bacterial inoculants (105 colony-forming units (CFU) g−1 fresh matter), and the bags were sealed with a BH 950 vacuum sealer (Panasonic, Osaka, Japan). Small-scale silage samples in a room at ambient temperature were collected at days 30 and 60 of the ensiling process.