Isolation and in-vitro characterization of extracellular phytase producing bacterial isolates for potential application in poultry feed.

BACKGROUND: Phytase catalyses the breakdown of complex organic forms of phosphorous into simpler forms by sequential hydrolysis of phosphate ester bonds to liberate the inorganic phosphate. Supplementation of feeds with bacterial phytase therefore could enhance the bioavailability of phosphorus and micronutrients. Hence, the aim of this study was to isolate and characterize phytase producing bacteria from rhizosphere soil, fresh poultry excreta, and cattle shed to evaluate their potential in improving poultry feeds. Phytase producing bacteria were isolated using wheat bran extract medium. RESULTS: A total of 169 bacterial isolates were purified and screened for phytase activity. Out of these, 36 were confirmed as positive for phytase enzyme activity. The bacterial isolates were identified by cultural, morphological, and biochemical features. The isolates were also identified by using 16 S rRNA gene sequencing. The bacterial isolates (RS1, RS8, RS10 and RS15) were provided with gene bank database accession numbers of MZ407562, MZ407563, MZ407564 and MZ407565 respectively. All isolates increased phytase production when cultured in wheat bran extract medium (pH 6) supplemented with 1% (wt/v) galactose and 1% (wt/v) ammonium sulphate incubated at 50oC for 72 h. Proximate composition analysis after supplementation of phytase showed that phytase supplementation improved bioavailability of phosphorus, calcium, potassium and sodium in poultry feed. CONCLUSIONS: Overall, this study showed that the nutritional value of poultry feed can be improved using microbial phytase enzyme which reduces the cost of supplementation with inorganic phosphate.

Molecular Characterization of Fermenting Yeast Species from Fermented Teff Dough during Preparation of Injera Using ITS DNA Sequence.

Identification of the yeast responsible for Injera fermentation is important in order to be more consistent and for scale-up of Injera production. In this study, yeast were isolated and identified from fermenting teff dough sample collected from household, hotels, and microenterprises, Addis Ababa. Initially, the yeast obtained from fermenting teff dough of different sources were selected on the basis of their CO2 production potentials. Its DNA sequencing of isolated yeast identified Pichia fermentans, Pichia occidentalis, Candida humilis, Saccharomyces cerevisiae, and Kazachstania bulderi. The association of identified yeast to their sources indicated the presence of Pichia fermentans in fermenting dough samples collected from all sources whereas Kazachstania bulderi, Saccharomyces cerevisiae, and Candida humilis were shown to be present in samples collected from households, hotels, and microenterprises, respectively. The phenotypes and CO2 production potentials of this yeast were also documented. This study has confirmed the presence of different yeast species in the fermentation of teff dough and hinted the complex nature of Injera dough fermentation.

Prevalence of Smear-Positive Tuberculosis among Patients Who Visited Saint Paul's Specialized Hospital in Addis Ababa, Ethiopia.

BACKGROUND: Tuberculosis (TB) continues to be a health problem in both developed and developing countries, including Ethiopia. OBJECTIVE: In this study, the prevalence of smear-positive tuberculosis among presumptive TB cases who visited the hospital was assessed. METHOD: Acid fast bacilli (AFB) test was performed on samples collected from 200 presumptive TB cases. Data were analyzed using appropriate statistical tools. RESULT: Among 200 presumptive TB cases, 10% (20 individuals) (60% were male and 40% were female) were found to be positive for the AFB. Of these AFB positive subjects, 11.2% and 6.3% were from urban and rural areas, respectively. Among 20 AFB positive cases, 45% (9), 45% (9), and 10% (2) were HIV positive, HIV negative, and with HIV status unknown, respectively. The highest AFB positive cases were found within age group between 25 and 44 years (70%) and followed by age above 40 years (30%). It was found out that 75% (15), 15% (3), 5% (1), and 5% (1) were unemployed, government employed, student, and nongovernment employed, accordingly. CONCLUSION: This study indicated higher level of AFB positive cases within age groups of 25-44 and 65-74 years and also exhibited higher prevalence of TB cases from urban areas.