Process development of oxalic acid production in submerged culture of Aspergillus niger F22 and its biocontrol efficacy against the root-knot nematode Meloidogyne incognita

Abstract

Oxalic acid has potent nematicidal activity against the root-knot nematode Meloidogyne incognita. In this study, fermentation parameters for oxalic acid production in submerged culture of Aspergillus niger F22 at 23, 25, and 30 °C were optimized in 5-L jar fermenters. The viscosity of the culture broth increased with increasing temperature. There was a negative correlation between oxalic acid production and the apparent viscosity; high volumetric productivity of oxalic acid was obtained at low apparent viscosity (less than 1000 cP), with a productivity of more than 100 mg/L h. When the apparent viscosity was over 2500 cP, the volumetric productivity decreased below 50 mg/L h. In addition, the volumetric mass transfer coefficient, K a, positively correlated with volumetric productivity. When the K a value increased from 0.0 to 0.017 /s, the volumetric productivity proportionally increased up to 176 mg/L h. When the temperature decreased, K a increased due to the decrease in viscosity, leading to increased volumetric productivity. The highest productivity of 7453.3 mg/L was obtained at the lowest temperature, i.e., 23 °C. The nematicidal activity of culture filtrate was proportional to the content of oxalic acid. Based on a constant impeller tip speed, oxalic acid production was successfully scaled up to a 500-L pilot vessel, producing a final concentration comparable to that in the 5-L jar.

Effective approach to organic acid production from agricultural kimchi cabbage waste and its potential application

“…The development of safe and eco-friendly nematicides has become an urgent issue in the field of biological control. Recently, the nematicidal activity of organic acids has been extensively reported [ 12 , 13 ].…”

“…Organic acids are widely used in the chemical, food, cosmetic, pharmaceutical, and beverage industries owing to their various functional properties [ 11 ]. Furthermore, the nematicidal effect of organic acids in the field of biological control has been extensively reported [ 12 , 13 ]. The global organic acid market was estimated to reach $6.94 million by 2016 and is expected to increase annually to $12.54 billion by 2026, based on the organic acid market analysis report [ 14 ].…”

Efficient gene deletion and replacement in Aspergillus niger by modified in vivo CRISPR/Cas9 systems

“…Aspergillus niger, as a member of filamentous fungi, is widely used to produce and secrete a variety of bioactive substance including organic acids, like citric acid (Wang et al 2017), oxalic acid (Lee et al 2018), gallic acid (Mata-Gomez et al 2015) as well as many carbohydrate-active enzyme (CAzymes), such as glucoamylase (Suyama et al 2017), glucose oxidase (Zhu et al 2018), and amylase (Varalakshmi et al 2009), which are valuable in industry especially food industry. And it is generally recognized as safe (GRAS) by the United States Food and Drug Administration.…”

Intergrated Metagenomics and Metabolomics Analysis Discovers Nematicidal Microbes, Enzymes and Metabolites From the Plant Rhizosphere Microbiota

“…[5, 49-51]. Aspergillus, Lactobacillus brevis andLysobacter capsici showed strong nematicidal activity and could inhibit the egg hatch of Meloidogyne spp., and their nematicidal activities were derived mainly from organic acids[7,52,53]. Many soil microorganisms such as Acinetobacter spp., Microbacterium sp., Enterobacter spp., Pantoea agglomerans, Pseudomonas putida and Sinorhizobium fredii, could induce systemic resistance in plants against the root-knot nematodes infection[54][55][56][57].…”