Assessment of Phosphorus Mobilizing Capacity of Bacillus spp. Isolated from Mangrove Rhizospheric Sediment and its Potential Application in Aquaculture

Abstract

Background: Phosphatase producing bacteria (PPB) plays a major role in mineralising organic P into inorganic form. Though application of bacterial biofertilizers are practiced in agriculture, their application is very limited in aquaculture. Method: The PPB isolates were screened and isolated from rhizospheric sediment of mangrove, Avicennia marina of Ennore creek, Tamil Nadu. Their P transformation potential and the possibilities of their application in aquaculture to mineralise organic P to inorganic P were studied. Result: Twenty PPB isolates were screened in the study site and their Alkaline Phosphatase (ALP) activity was in the range of 13.6-20.4 µmol.ml-1.hr-1. Out of this, five Bacillus sp isolates were selected to assess their P transformation potential at various salinity. The P mobilizing potential of these isolates were compared with the commercial PPB following a microcosm study for a period of 14 days. During the study period, there is a significant increase in phosphorus in water as well as ALP activity and available phosphorus concentrations in sediments were observed between control and treatment tanks. Among the treatment groups, B. subtilis treatment tanks showed maximum P in water ie. 1.60mg.L-1, followed by B. altitudinis –1.49mg.L-1; B. pumilus –1.47mg.L-1; the soil ALP activity was in the order of commercial P products greater than B. pumilus greater than B. subtilis greater than B. paramycoides greater than B. altitudinis greater than B. aryabhattai. In terms of available phosphorus content in sediments on 14th day, there is no significant difference observed between B. pumilus and commercial product with respect to available P content of sediment.

Biofertilization with Liquid Vermicompost-Activated Biochar Enhances Microbial Activity and Soil Properties

“…On the other hand, microbial UA is a key component of soil biological activity, since it promotes nutrient cycling and the enhancement of N in the soil, and thus contributes to the maintenance of soil health and fertility [91]. In this regard, several members of the phylum Bacillota, including B. subtilis, B. cereus, and P. aryabhattai, are known for their high APA and UA [92][93][94][95]. Moreover, other identified bacterial species from the phylum Pseudomonadota, including B. bullata as well as several Brucella and Pseudomonas species, can produce diverse types of phosphatases [93,[96][97][98][99][100] and ureases [101,102].…”

Isolation of Phosphorus Solubilizing Bacteria from Mangrove Rhizospheric Sediment and its Potential Application in Aquaculture

“…Several studies were carried out to screen PSB from a variety of land ecosystems in search of P mineralising and solubilising microbes for their application as biofertilizers in agriculture (Alori et al, 2017;Garcia -Fraile et al, 2017;Kalayu 2019;Aruna and Jain, 2021). Recent researches are focusing on the screening of salt tolerant microbes in warrant of their application in salt affected land to improve soil fertility (Iwaoka et al, 2018;Zhang et al, 2018;Egamberdieva et al, 2019;Aruna et al, 2023). Very few studies have been carried out to screen PSB in aquatic ecosystems, particularly from mangrove areas.…”