Isolation and identification of phosphate solubilizing bacteria from indigenous microorganisms (IMO) of cow rumen in East Java, Indonesia as eco-friendly biofertilizer

Abstract

Aims: Phosphate is an essential nutrient required for plant growth, but its solubility in the soil is relatively low (0.1%). Microbes can dissolve phosphate to meet crop requirements. This study aimed to isolate phosphate solubilizing bacteria from indigenous microorganisms (IMO) of cow rumen. Methodology and results: The selection of isolates on a Pikovskaya medium was using a clear zone index and a spectrophotometer for phosphate solubilization measurements. Hypersensitivity was tested on tobacco leaves and tested antagonists within isolates. The results found that four selected isolates had the highest phosphate dissolving potential, namely, MTA1, SMAD1, SMAD2, and SMAD3. The culture of selected isolates on plate media showed that the morphological characters of the four colonies are the same. They had round form (circular), the edge of the colony were smooth, flat elevation, white and cream color. Isolate MTA1 had the highest phosphate solubilizing activity compared to the others. The isolate that showed the highest phosphate solubilizing activity were identified based on 16S rRNA gene. The result of molecular identification showed that strain MTA1 was closely related to Lactobacillus plantarum with a similarity level of 99%. L. plantarum performed the highest ability to form a clear zone (7.66 mm). The highest concentration of soluble phosphate was observed on day 5 (278.42 mg/L). Conclusion, significance, and impact of the study: Lactobacillus plantarum which was isolated from the IMO of cow rumen in East Java, Indonesia was identified as one of the phosphate solubilizing bacteria that are useful for the development of eco-friendly biofertilizer. The application of phosphate solubilizing microbes can be used to increase the soil fertility.

Assessing Methodological Variability in Gut Microbiome Studies: Lessons from Southeast Asian for Effective Conservation Strategies

“…Notably, all the research on invertebrates and fish employs invasive methods while non-invasive approaches are generally preferred for larger animals such as mammals. Only a limited number of studies focusing on mammals have gathered microbes directly from specific parts of the gastrointestinal tract, and these studies have primarily centred on food-producing animals such as organs of cows, pigs, and buffalo sourced from the traditional market [33,36,41]. This preference also can be attributed to the protected status of many wildlife species and the potential risks involved, such as the possibility of injuries or fatalities, which could have significant ethical and conservation implications, especially for endangered or threatened species [7,15].…”

“…But Hameed et al [53] suggested that combining conventional and molecular techniques can help achieve the accuracy, rapidness, and reliability of microbiome results. Hence, the technique also been proven in a few groups of wildlife studies throughout Southeast Asia [23,29,33,51,54,55].…”

“…Some of the studies focused on ruminants such as cows (eg. Teo et al [32], Astriani et al [33], Hang et al [34], and Prasetiyono et al [35]) and buffaloes (eg. Harsojo [36], and Agustina et al [37]), poultries such as chickens by Pin Viso et al [38] and duck (eg.…”