Citric acid production from Aspergillus niger MT-4 using hydrolysate extract of the insect Locusta migratoria

Abstract

Citric acid (CA) is the most important organic acid used in the food and other industries. Locusta migratoria is an insect species, which has rich nutritional composition (especially protein) and cultivated in some countries. Therefore, the present study investigated the usability of hydrolysate extract of L. migratoria biomass as substrate for the production of CA from Aspergillus niger MT-4. The insect extract (IE) was found to be rich in ash (34.9 g/100 g), protein (35.6 g/100 g) and mineral contents. Yeast extract was found to be the most favorable substrate for biomass production, whereas the maximum production of CA (41.8 g/L) was achieved in the medium containing IE. Besides, uniform pellets with the smallest size (4 mm) were observed in IE medium. It was thought that rich magnesium (6.78 g/100 g) and manganese (1.14 g/100 g) contents of IE increased the production of CA, resulting in the formation of small uniform pellets. This is the first report on the effect of protein-rich insect biomasses on the production of CA. In this regard, L. migratoria biomass was tested for the first time as a CA-production substrate.

USE OF MULBERRY POMACE AS SUBSTRATE FOR CITRIC ACID PRODUCTION BY Aspergillus niger MT-4

“…Microorganism, materials and chemicals Aspergillus niger MT-4 was obtained from Professor Mesut Taskin from the Department of Molecular Biology and Genetics, Atatürk University, Turkey (Taskin et al (2013). MP was obtained from a commercial company producing mulberry pekmez in Erzurum province (Turkey).…”

“…Most of CA is used in food (about 70%) and pharmaceutical (12%) industries (Darouneh et al 2009). The production of CA is carried out by extraction from plants or by chemical synthesis and microbial fermentation but about 99% of the production is achieved via microbial fermentation (Taskin et al 2013, Arslan et al 2016. Several microorganisms such as bacteria, filamentous fungi and yeasts are capable of producing CA.…”

“…For example, filamentous fungi such as Aspergillus niger van Tieghem, A. wenti Wehmer, A. foetidus Thom (Soccol et al 2006, Show et al 2015. Despite the variety of these different producers, microbial production of CA is mainly performed using A. niger since this filamentous fungus is able to use numerous cheap raw materials and to accumulate CA with higher yields (Soccol et al 2006, Angumeenal & Venkappayya 2013, Taskin et al 2013, Arslan et al 2016. Microbial CA production is achieved by three different fermentation techniques as surface fermentation, submerged fermentation and solid-state fermentation.…”

“…Growth substrates make up the major part of the production costs in fermentation studies. Therefore, selection of a low-cost substrate is considered as a major aspect in microbial fermentation studies (Taskin et al 2013). For example, with the aim of reducing the production cost in the production of CA, cheap agricultural wastes and/or byproducts such as beet molasses, black strap molasses, cane molasses, n-paraffin, glycerol, whey and waste oil are usually preferred as substrate (Soccol et al 2006, Torrado et al 2011Show et al 2015, Arslan et al 2016).…”

Sheep wool protein hydrolysate: a new peptone source for microorganisms

“…The final concentration of spore suspension obtained was adjusted to about 10 6 spores per mL with sterile saline water. 1 mL of the homogenized spore suspension was used for inoculation of peptone medium …”