Effect of time and diet change on the bacterial community structure throughout the gastrointestinal tract and in faeces of the northern brown bandicoot, Isoodon macrourus

A significant gap, in not only peramelid nutritional physiology but marsupial nutrition as a whole, is the lack of information relating to microorganisms of the gastrointestinal tract. This research is a preliminary investigation that will provide a baseline for comparisons among peramelids. The high degree of 16S rRNA gene clones identified in this research that are closely related to culturable bacteria suggests that additional research will enable a more complete description of the gastrointestinal bacteria of I. macrourus. Most identifiable clones belonged to Clostridium and Ruminococcus. This research has confirmed that the hindgut of I. macrourus, the caecum, proximal colon and distal colon, are the main sites for microbial activity.

A morphological and genetic description of pentastomid infective nymphs belonging to the family Sebekidae Sambon, 1922 in fish in Australian waters

Infective nymphal stages of the family Sebekidae Sambon, 1922 are reported from four species of fish in Australian waters for the first time. Infected fish were collected from locations in Western Australia, the Northern Territory and north Queensland. The infective nymphs of Alofia merki Giglioli in Sambon, 1922 and Sebekia purdieae Riley, Spratt et Winch, 1990 are reported and described for the first time. The remaining specimens were identified as belonging to the genus Sebekia Sambon, 1922 based on the combination of buccal cadre shape, shape and size of hooks, and overall body size, but could not be attributed to any of the other species of Sebekia already reported due to missing required morphological features. DNA sequences of members of the family Sebekidae are presented for the first time. The lack of knowledge on the pentastome fauna of wild crocodiles, and any potential intermediate hosts, in northern Australia, is also outlined.

Production responses of reproducing ewes to a by-product-based diet inoculated with the probiotic Bacillus amyloliquefaciens strain H57

The potential application of the spore-forming probiotic Bacillus amyloliquefaciens strain H57 (H57) as a novel probiotic for ruminants was evaluated in reproducing ewes. Performance responses were determined by delivering H57 in a pelleted diet based mainly on palm kernel meal (PKM) and sorghum grain. PKM is an agro-industrial by-product with a reputation for poor palatability and the availability of the starch in sorghum grain can be limited in ruminants. The hypothesis was that H57 improves the feeding value of a relatively low quality concentrate diet. Twenty-four first-parity white Dorper ewes were fed PKM-based pellets manufactured with or without H57 (109 cfu/kg pellet) in late pregnancy. During this phase of late pregnancy, the H57 ewes ate 17% more dry matter (1019 vs 874 g/day, P = 0.03), gained more weight (194 vs 30 g/day, P = 0.008) and retained more nitrogen (6.13 vs 3.34 g/day, P = 0.01), but produced lambs with a similar birthweight (4.1 vs 4.2 kg, P = 0.73). Rumen fluid collected from H57 ewes in late pregnancy had higher pH (7.1 vs 6.8, P = 0.07), acetate : propionate ratio (3.4 vs 2.7, P = 0.04), lower ammonia (69 vs 147 mmol/L, P = 0.001) and total volatile fatty acid concentrations (40 vs 61 mg/L, P = 0.02). The digestibility of dry matter, organic matter and fibre were similar between the two groups. The lambs of the H57 ewes grew faster than those of the Control ewes for the first 21 days of lactation (349 vs 272 g/day, P = 0.03), but not thereafter. H57 can improve feed intake and maternal liveweight gain in late pregnancy of first-parity ewes fed a diet based on PKM.

Characterization, development and multiplexing of microsatellite markers in three commercially exploited reef fish and their application for stock identification

Thirty-four microsatellite loci were isolated from three reef fish species; golden snapper Lutjanus johnii, blackspotted croaker Protonibea diacanthus and grass emperor Lethrinus laticaudis using a next generation sequencing approach. Both IonTorrent single reads and Illumina MiSeq paired-end reads were used, with the latter demonstrating a higher quality of reads than the IonTorrent. From the 1–1.5 million raw reads per species, we successfully obtained 10–13 polymorphic loci for each species, which satisfied stringent design criteria. We developed multiplex panels for the amplification of the golden snapper and the blackspotted croaker loci, as well as post-amplification pooling panels for the grass emperor loci. The microsatellites characterized in this work were tested across three locations of northern Australia. The microsatellites we developed can detect population differentiation across northern Australia and may be used for genetic structure studies and stock identification.

Near complete genome sequence of the animal feed probiotic, Bacillus amyloliquefaciens H57

Bacillus amyloliquefaciens H57 is a bacterium isolated from lucerne for its ability to prevent feed spoilage. Further interest developed when ruminants fed with H57-inoculated hay showed increased weight gain and nitrogen retention relative to controls, suggesting a probiotic effect. The near complete genome of H57 is ~3.96 Mb comprising 16 contigs. Within the genome there are 3,836 protein coding genes, an estimated sixteen rRNA genes and 69 tRNA genes. H57 has the potential to synthesise four different lipopeptides and four polyketide compounds, which are known antimicrobials. This antimicrobial capacity may facilitate the observed probiotic effect.