Screening for Tannin Degradation by Rumen and Faecal Samples of Wild and Domestic Animals in Ethiopia

Summary Tannins limit the use of fodder trees as feed for ruminants. Removal of the effects of tannins would thus improve the nutritional quality of these trees. This prompted the study to evaluate the effect of rumen or faecal mixed cultures from different animals on tannin degradation. Tannin extracts, tannic acid and gallic acid were used to enrich media to assess if rumen or faecal mixed cultures could degrade the phenolic compounds. Rumen fluid of Acacia-adapted sheep, sheep fed on wheat bran, bush duikers (Sylvicapra grimmia) and goats fed on Leucaena pallida and Sesbania goetzei were separately inoculated into Growth Study Medium (GSM) and incubated for 5-15 days. Faecal samples from dikdik (Madoqua guentheri), camel (Camelus dromedarius), zebra (Equus quagga), Grant’s gazelle (Gazella granti) and hartebeest (Alcelaphus buselaphus) were also separately inoculated into GSM media and incubated from 3-5 days. TLC results showed that mixed cultures from rumen fluids of Acacia-adapted sheep, sheep on wheat bran, goats on Leucaena pallida and Sesbania goetzei partially hydrolysed tannic acid to pyrogallol. Complete degradation of the heterocyclic ring in tannic acid and gallic acid was achieved by the mixed cultures from the faecal samples of dikdik and this was confirmed by HPLC. Mixed cultures from faecal samples of camel hydrolysed gallic acid to phloroglucinol. This study has demonstrated that faecal microorganisms of Ethiopian dikdik could completely degrade hydrolysable tannin.     

非洲菊盘状花雄蕊发育与舌状花生长着色的对应关系

非洲菊(Gerbern hybrida)头状花序由外轮舌状花和内轮盘状花构成。通过观察内轮盘状花雄蕊花粉囊和花粉粒的形态结构与发育顺序,和测定外轮舌状花花瓣的长度、宽度、花色素苷含量等,对它们之间的对应关系进行了研究。花序外轮舌状花花瓣开始着色时为P3期,此时第1轮盘状花出现成熟花粉粒。研究明确了内轮盘状花花粉粒发育与外轮舌状花生长时期和花色素苷积累的对应关系。     

A new technique for simultaneous collection of macroalgal propagules in the water column

A Simultaneous Collection Module (SCM) was designed to concurrently collect multiple samples of macroalgal propagules, and to evaluate their abundance and spatial distribution in the water column. The basic sampling units are water collectors (tubes), held together to form an evenly spaced grid forming a spatial array with three dimensions. Each collector in the module possesses a simultaneous closing mechanism. The water collected in each tube is then filtered and the propagules retained on each filter cultivated under controlled conditions. The sampling system was deployed in the field in central Chile. Results suggest the system is an efficient collector, able to provide data on time-space changes of macroalgal propagules in the water column.     

Micro-distribution of Soil Inhabiting Tardigrades (Tardigrada) in a Sub-alpine Coniferous Forest of Japan

Micro-distribution of soil inhabiting tardigrades was studied in a sub-alpine coniferous forest (alt. 1,840 m a. s. l.) on the eastern slope of Mt. Yatsugatake, Central Japan. Eight cylindrical soil samples were taken from the forest floor. Each sample was divided into 10 slice samples of 1 cm thick. Tardigrades were extracted from samples by Baermann funnels, identified to specific level and counted. The average number of tardigrades in the study site is 74,058/m². High densities sometimes occurred at depths greater than 5 cm. Consequently for investigating tardigrade populations, 5cm depth core sampling is insufficient in this type of habitat. Composition of the main groups of species reveals that shallow layers (1, 2 or 3 cm depth) are frequently dominated by the Diphascon-group. Macrobiotus-group species generally occurred in higher abundance in the deeper layers. It is very interesting that there are some different patterns of soil micro-distribution in tardigrade species.     

Genotoxicity assessment in aquatic environments under the influence of heavy metals and organic contaminants

The genotoxicity of river water and sediment including interstitial water was evaluated by microscreen phage-induction and Salmonella/microsome assays. Different processes used to fractionate the sediment sample were compared using solvents with different polarities. The results obtained for mutagenic activity using the Salmonella/microsome test were negative in the water and interstitial water samples analysed using the direct concentration method. The responses in the microscreen phage-induction assay showed the presence of genotoxic or indicative genotoxic activity for at least one water sample of each site analysed using the same concentration method. Similar results were obtained for interstitial water samples, i.e. absence of mutagenic activity in the Salmonella/microsome test and presence of genotoxic activity in the microscreen phage-induction assay. Metal contamination, as evidenced by the concentrations in stream sediments, may also help explain some of these genotoxic results. Stream sediment organic extracts showed frameshift mutagenic activity in the ether extract detected by Salmonella/microsome assay. The concentrates evaluated by microscreen phage-induction assay identified the action of organic compounds in the non-polar, medium polar and polar fractions. Thus, the microscreen phage-induction assay has proven to be a more appropriate methodology than the Salmonella/microsome test to analyse multiple pollutants in this ecosystem where both organic compounds and heavy metals are present.     

Some Tests for k£2 Upper Outliers in an Exponential Sample

The sequential procedure for testing up to k upper outliers proposed by Kimber (1982) for one-parameter exponential distribution is modified to a two-parameter exponential distribution. Further null distributions of some test statistics for an upper outlier-pair in a complete or censored sample from a two-parameter exponential distribution are given. Percentage points of the statistic T₁ are tabulated.     

Synthesis,antimicrobial and molecular docking studies of enantiomerically pure N-alkylated β-amino alcohols from phenylpropanolamines

Enantiomerically pure N-alkylated β-amino alcohols 1a, 1a′, 1c, 1c′, 1d, 1d′, 1e and 1e′, with ee 100% have been synthesized from phenylpropanolamines 2. Effect of the neighboring chiral environment on the newly formed chiral center has been studied experimentally and concluded that the newly formed chiral center’s absolute configuration is opposite to the adjacent (α- or β-) chiral environment. The antimicrobial activity of the synthesized β-amino alcohols were screened using in vitro disc diffusion method and variable antimicrobial activities were shown for 1a, 1a′, 1c, 1c′, 1d, 1d′, 1e & 1e′ and amongst them 1d & 1d′ exhibited significant activity against bacteria and fungi. In silico studies revealed all the synthesized β-amino alcohols 1a–e and 1a′–e′ have shown good binding energies ranging from −7.38 to −6.09 kJ/mol towards the target receptor DNA topoisomerase IV and 1d′ has shown maximum binding energy −7.38 kJ/mol.