Biotechnology Department, College of Natural and Computational Sciences, Institute of Biotechnology, Addis Ababa University, Addis Ababa, Ethiopia.
Biotechnology and Bioprocess Center of Excellence, Addis Ababa Science and Technology University, Addis Ababa, Ethiopia.
BMC Microbiol. 2023 Oct 17;23(1):296. doi: 10.1186/s12866-023-03041-2.
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.
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 50C 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.
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.
植酸酶通过顺序水解磷酸酯键将复杂的有机磷形式分解为更简单的形式，从而催化磷的分解。因此，在饲料中添加细菌植酸酶可以提高磷和微量元素的生物利用率。因此，本研究的目的是从根际土壤、新鲜家禽粪便和牛棚中分离和鉴定产植酸酶的细菌，以评估其在改善家禽饲料中的潜力。使用麦麸提取物培养基分离产植酸酶的细菌。
共纯化并筛选了 169 株细菌分离物以检测植酸酶活性。其中，36 株被确认为植酸酶活性阳性。通过文化、形态和生化特征对细菌分离物进行鉴定。通过 16S rRNA 基因测序对分离物进行鉴定。细菌分离物（RS1、RS8、RS10 和 RS15）分别被赋予 MZ407562、MZ407563、MZ407564 和 MZ407565 的基因银行数据库登录号。所有分离物在添加 1%（wt/v）半乳糖和 1%（wt/v）硫酸铵的麦麸提取物培养基（pH 6）中培养时，植酸酶产量增加，在 50°C 下孵育 72 小时。补充植酸酶后的近似成分分析表明，植酸酶补充剂提高了家禽饲料中磷、钙、钾和钠的生物利用率。
总的来说，这项研究表明，使用微生物植酸酶可以提高家禽饲料的营养价值，从而降低补充无机磷的成本。
