Isolation, Characterization, and Optimization of Glucoamylase – Producing Bacteria from Fruit Waste Soil for Industrial Applications

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ABSTRACT

Glucoamylases are exo-amylases that play a crucial role in starch hydrolysis, converting it into glucose, a fundamental process in industries such as food, biofuels, bioplastics, and chemicals. Fruit waste soil, rich in organic matter, harbors diverse microbial communities capable of producing industrially significant enzymes. This study aimed to isolate, characterize, and optimize glucoamylase-producing bacteria from fruit waste soil collected from Tasawade MIDC, Karad. Four bacterial isolates (T2, T3, T4, T5) were screened for glucoamylase production using starch agar medium, with isolate T5 exhibiting the highest enzymatic activity. The enzyme production was optimized under varying conditions of pH, temperature, salt concentration, metal ions, and substrate concentration. Maximum enzyme activity was observed at pH 6, 25°C, 0.2 mg/ml salt concentration, and 2.5 mg/ml substrate concentration, with MgCl₂ (0.3 mg/ml) enhancing enzyme activity. Among the isolates, T5 demonstrated superior glucoamylase production (176.45 U/ml/min) and specific activity (309.56 U/mg). Morphological and biochemical characterization revealed that T5 was a Gram-positive, non-motile coccus, while T2 was a Gram-positive, motile, spore-forming rod. The stability and efficiency of the isolated glucoamylase under diverse conditions suggest its potential for industrial applications. Further research on large-scale production, purification, and kinetic studies could enhance its utility in starch processing, biofuel production, and other biotechnological industries. This study highlights the significance of microbial enzymes from organic waste sources as sustainable and cost-effective alternatives for industrial processes.

Significance of the Study:

This study highlights the potential of glucoamylase-producing bacteria from fruit waste soil as sustainable biocatalysts for industrial starch hydrolysis. By optimizing enzyme production, the research offers an eco-friendly alternative to chemical processes in food, biofuels, and bioplastics industries. Utilizing organic waste reduces environmental burden while providing cost-effective enzyme sources. The high activity and stability of the isolated glucoamylase (T5) under varied conditions underscore its industrial applicability, supporting greener biotechnology and waste valorization strategies for large-scale enzyme production.

Summary of the Study:

The study isolated and characterized glucoamylase-producing bacteria from fruit waste soil in Tasawade MIDC, Karad. Among four isolates, T5 showed the highest activity (176.45 U/ml/min) and specific activity (309.56 U/mg). Optimal conditions were pH 6, 25°C, 0.2 mg/ml salt, and 2.5 mg/ml substrate, with MgCl₂ enhancing activity. T5, a Gram-positive coccus, demonstrated robust enzyme stability. The findings suggest its industrial potential in starch processing and biofuels, emphasizing sustainable microbial enzyme production from organic waste for eco-friendly biotechnological applications.