Abstract

Phosphorus is an essential nutrient element for all life forms. Phosphate solubilizing bacteria play an important role in plant growth and development and are able to solubilize unavailable forms of phosphates by excreting organic acids and phosphatase enzymes mainly acid phosphatase through the process of solubilization and mineralization. In this study, 17 potential phosphate solubilizing bacteria were identified using 16SrRNA gene sequence from Thenzawl paddy field of Mizoram, India. Assessment of acid phosphatase (APase) activity and Indole-3-acetic acid (IAA) production under induced heavy metals stresses were done in vitro condition. APase activity was determined by performing p-nitrophenyl phosphate assay of the bacterial broth culture and IAA production was checked using Salkowski’s reagent. Maximum APase activity was seen in Burkholderia gladioli strain MZUTZ15 (35.884 µg p-NP ml⁻¹hr⁻¹) while maximum IAA production was seen in Burkholderia sp. strain MZUTZ19 (31.201 µg ml ⁻¹) under control experiment. The APase activity and IAA production of all tested isolates were found to be adversely affected by the presence of different concentration of heavy metals such as copper (Cu) and iron (Fe) in the culture medium compared to control.

摘要

磷是所有生命形式必不可少的营养元素。溶磷菌在植物生长发育中起着重要作用，能够通过增溶和矿化过程排出有机酸和磷酸酶，主要是酸性磷酸酶，从而溶解不可利用的磷酸盐。在这项研究中，使用来自印度米佐拉姆邦 Thenzawl 稻田的 16SrRNA 基因序列鉴定了 17 种潜在的磷酸盐溶解细菌。在体外对诱导的重金属胁迫下酸性磷酸酶 (APase) 活性和吲哚-3-乙酸 (IAA) 产量进行评估状况。APase 活性通过对细菌肉汤培养物进行对硝基苯磷酸盐测定来确定，IAA 生产使用 Salkowski 试剂进行检查。最大AP酶的活性被认为在唐菖蒲伯克霍尔德菌菌株MZUTZ15（35.884微克P-NP毫升^-1小时^-1），而最大IAA产量中所见伯克氏菌属一个藻。在对照实验中菌株 MZUTZ19 (3​​1.201 µg ml ^-1 )。发现与对照相比，培养基中不同浓度的重金属如铜 (Cu) 和铁 (Fe) 的存在对所有测试分离株的 APase 活性和 IAA 产生产生不利影响。