Characteristics of Gorilla-Specific Lactobacillus Isolated from Captive and Wild Gorillas

Abstract

Lactic acid bacteria (LAB) reside in a wide range of mammals, such as autochthonous intestinal bacteria. In this paper, we present the phenotypic and phylogenetic characteristics of gorilla-specific LAB. Lactobacillus gorillae-previously isolated from the wild and captive western lowland gorillas (Gorilla gorilla gorilla)-were successfully isolated from wild mountain gorillas (Gorilla gorilla beringei) in addition to other captive and wild western lowland gorillas. The strains from wild gorillas could ferment D-xylose, arbutine, cellobiose, and trehalose better than those from captive gorillas. By contrast, tolerance to NaCl was higher in isolates from captive gorillas than in those from wild gorillas. This tendency may have been induced by regular foods in zoos, which contain sufficient amount of salts but less amount of indigestible fiber and plant secondary metabolites compared to foods in the wild. All strains of L. gorillae showed inhibitory activities to enteric pathogenic bacteria; however, the activity was significantly higher for strains from wild gorillas than for those from captive gorillas. This may have been induced by the captive condition with routine veterinary intervention. Since L. gorillae can grow in the gastrointestinal tract of gorillas in captivity, the strains from wild mountain gorillas are potential probiotics for gorillas under captive conditions.

Keywords: Lactobacillus gorillae; antipathogenic infection; mountain gorilla; phenotypic characteristic; phylogeny; western lowland gorilla.

Figure 1

Phylogenetic tree based on partial 16S rRNA gene sequences showing the relationships between L. gorillae and members of related Lactobacillus species. The tree was conducted by neighbor-joining method. L. delbruekii subsp. delbrueckii JCM 1012^T was used as an out-group. Bootstrap values (>50%) based on 1000 replicates are shown at branch nodes. Bars represent 0.02 substitutions per nucleotide position.

Figure 2

Antimicrobial activities of strains from gorillas. MW—strains from wild mountain gorillas (n = 5); WW—strains from wild western lowland gorillas (n = 5); WC—strains from captive western lowland gorillas (n = 8). In the box plot, the line in the middle of the box represents the median; the upper and lower perimeters of the box represents the 75th and 25th centiles, respectively; and the tails represent 2.5th and 97.5th centiles, respectively. ** p < 0.01.