No abstract

Bats are highly diverse and ecologically valuable mammals. They serve as host to bacteria, viruses and fungi that are either beneficial or harmful to its colony as well as to other groups of cave organisms. The bacterial diversity of two bat guano samples, C1 and C2, from Cabalyorisa Cave, Mabini, Pangasinan, Philippines were investigated using 16S rRNA gene amplicon sequencing. V3-V4 hypervariable regions were amplified and then sequenced using Illumina MiSeq 250 PE system. Reads were processed using Mothur and QIIME pipelines and assigned 12,345 OTUs for C1 and 5,408 OTUs for C2. The most dominant OTUs in C1 belong to the Proteobacteria (61.7%), Actinobacteria (19.4%), Bacteroidetes (4.2%), Firmicutes (2.7%), Chloroflexi (2.5%), candidate phylum TM7 (2.3%) and Planctomycetes (1.9%) while Proteobacteria (61.7%) and Actinobacteria (34.9%) dominated C2. Large proportion of sequence reads mainly associated with unclassified bacteria indicated possible occurrence of novel bacteria in both samples. XRF spectrophotometric analyses of C1 and C2 guano revealed significant differences in the composition of both major and trace elements. C1 guano recorded high levels of Si, Fe, Mg, Al, Mn, Ti and Cu while C2 samples registered high concentrations of Ca, P, S, Zn and Cr. Community structure of the samples were compared with other published community profiling studies from Finland (SRR868695), Meghalaya, Northeast India (SRR1793374) and Maharashtra State, India (CGS). Core microbiome among samples were determined for comparison. Variations were observed among previously studied guano samples and the Cabalyorisa Cave samples were attributed to either bat sources or age of the guano. This is the first study on bacterial diversity of guano in the Philippines through high-throughput sequencing.

We report here the draft genome sequences of six bacteria isolated from the near-bottom waters and surface sediments of the Benham Bank, Philippine Rise, Philippines. These genome sequences represent candidate novel species and/or strains from the families Flavobacteriaceae and Dermacoccaceae and the genera Idiomarina, Bacillus, and Vibrio.

Two nanocellulose-producing bacteria were isolated from separate local nata starter cultures and were characterized to determine their putative identity. The nanocellulose produced by the two bacterial isolates were compared to determine if differences between material properties and in vitro biocompatibility were species-dependent. Nanocellulose membranes were produced by inoculating the bacterial isolates to Hestrin–Schramm media using different carbon sources (glucose, mannitol and sucrose). The material properties of nanocellulose membranes were characterized using scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray dispersive spectroscopy, Calcofluor staining and water retention. The biocompatibility of the nanocellulose membranes was evaluated using MC3T3 pre-osteoblast cells and was analyzed using CCK-8 cell viability assay. Adhering cells were stained and viewed under confocal laser scanning microscope. A selected sample was implanted subcutaneously in Sprague Dawley rats for one week and four weeks to determine its in vivo biocompatibility. Hematoxylin and eosin staining of the subcutaneous tissue sections with implant was examined to visualize host cell behavior to the implant.

Streptomyces sp. strains AC1-42T and AC1-42W, isolated from bat guano from Cabalyorisa Cave, Mabini, Pangasinan, Philippines, are active against Bacillus subtilis subsp. subtilis KCTC 3135T.