Related Experiment Video
Updated: Jun 26, 2026
07:24
Production of Chemicals by Klebsiella pneumoniae Using Bamboo Hydrolysate as Feedstock
Published on: June 29, 2017
8.9K
Mixed-culture polyhydroxyalkanoate production with variable hydroxyvalerate content from agri-food residues
Claudia Magonara1, Elvis Montagnese1, Davide Bertasini1
1Department of Biotechnology, University of Verona, Verona, 37134, Italy.
Environmental Science and Pollution Research International
|April 16, 2025
Summary
This study valorizes agri-food residues into polyhydroxyalkanoates (PHAs), specifically polyhydroxybutyrate-co-hydroxyvalerate (PHBV). The research successfully produced PHBV with targeted hydroxyvalerate content for agricultural applications using mixed microbial cultures and various feedstocks.
Area of Science:
- Biotechnology and sustainable materials science.
- Microbial biopolymer production.
Background:
- Agri-food residues are abundant, underutilized biomass resources.
- Polyhydroxyalkanoates (PHAs) offer a biodegradable alternative to conventional plastics.
- Polyhydroxybutyrate-co-hydroxyvalerate (PHBV) provides enhanced flexibility compared to pure polyhydroxybutyrate (PHB).
Purpose of the Study:
- To produce polyhydroxyalkanoates (PHAs) with a specific hydroxyvalerate (HV) monomer content (25-35% w/w).
- To evaluate the feasibility of using diverse feedstocks, including agri-food residue fermentation fluids, for PHBV production.
- To tailor PHBV properties for agricultural material applications.
Main Methods:
- Utilized mixed microbial cultures under a feast/famine regime for PHA accumulation.
- Employed various feedstocks, from synthetic media to agri-food residue fermentation fluids.
- Analyzed chemical oxygen demand (COD) removal, hydroxyvalerate content, molecular weight, and bacterial community composition.
Main Results:
- Achieved the target hydroxyvalerate monomer content (25-35% w/w) in produced PHBV.
- Demonstrated high COD removal efficiencies (81.6-99.1%) with synthetic feed, and moderate efficiency (71.4-85.9%) with agricultural fermentate.
- Obtained molecular weights suitable for thermoplastic processing (352-1369 kDa) despite feedstock variations.
- Observed shifts in bacterial community composition, favoring PHA producers like Thauera and Paracoccus, with a decrease in diversity upon introduction of agricultural fermentate.
Conclusions:
- Agri-food residues can be effectively valorized into functional polyhydroxyalkanoates (PHBV).
- Mixed microbial cultures are capable of producing PHBV with tailored hydroxyvalerate content using diverse feedstocks.
- Further optimization is needed to enhance carbon uptake from agricultural feedstocks and maintain microbial diversity for consistent biopolymer production.
Keywords:
Agricultural residuesHydroxyvalerateMixed microbial culturesPolyhydroxyalkanoatesVolatile fatty acidsMore Related Videos
Related Concept Videos
01:27Microorganisms in Agriculture and Food industry
Microorganisms play a crucial role in agriculture and the food industry, contributing to soil fertility, crop protection, and food production. Their functions range from nitrogen fixation and biopesticide production to fermentation and food preservation, making them indispensable to sustainable farming and food safety.Role in AgricultureNitrogen-fixing bacteria, such as Rhizobium (symbiotic) and Azotobacter (free-living), convert atmospheric nitrogen into ammonia through biological nitrogen...
01:29Microbes in Food Production
Microbial fermentation is central to food biotechnology, enhancing flavor, texture, preservation, and stability. Fermentative microorganisms metabolize carbohydrates into organic acids, alcohols, and other metabolites that inhibit spoilage organisms and improve digestibility while contributing distinctive sensory qualities.In baking, amylases naturally present in flour hydrolyze starch into monosaccharides such as glucose, which Saccharomyces cerevisiae ferments anaerobically. Through...
01:25Microbes in Beverage Production
Alcoholic beverages such as wine, beer, and spirits are the products of microbial fermentation processes that transform simple sugars into ethanol and a wide array of complex flavor compounds. These transformations rely on the metabolic activities of specific yeasts and bacteria, which are selected and controlled to yield the desired beverage characteristics.Wine Fermentation and MaturationWine production begins with the crushing of grapes to release juice and pulp, forming a must that is...
01:27Microbes in the Production of Fermented Foods
Lactic acid bacteria (LAB) and molds are instrumental in fermenting plant-based foods to enhance preservation and ensure year-round availability. These microbial processes convert plant carbohydrates into organic acids and other metabolites that inhibit spoilage organisms and contribute to the sensory qualities of the final product.In sauerkraut production, cabbage goes through a microbial succession that starts with cocci such as Leuconostoc mesenteroides. These microbes begin fermentation by...
01:25Production of Organic Acids
Lactic acid, an important organic acid extensively applied in food, pharmaceutical, and biodegradable polymer industries, is primarily produced via microbial fermentation. This method is favored over chemical synthesis due to its environmental sustainability and capacity for enantiomerically pure product formation. Among various microbial processes, the fermentation of starch-based substrates stands out due to the abundance and renewability of raw materials like corn and potatoes.Hydrolysis of...
01:27Bioplastics
Bioplastics derived from microbial processes present a sustainable alternative to conventional petroleum-based plastics. Among these, polyhydroxyalkanoates (PHAs), particularly polyhydroxybutyrates (PHBs), have emerged as prominent candidates due to their biodegradability and biocompatibility. These polymers are synthesized by a variety of bacteria, such as Cupriavidus necator and Pseudomonas putida, which naturally accumulate PHAs as intracellular carbon and energy reserves, especially under...