Conversion of Squid Pen to Homogentisic Acid via Paenibacillus sp. TKU036 and the Antioxidant and Anti-Inflammatory Activities of Homogentisic Acid

Abstract

The culture supernatant of Paenibacillus sp. TKU036, a bacterium isolated from Taiwanese soils, showed high antioxidant activity (85%) when cultured in a squid pen powder (SPP)-containing medium at 37 °C for three days. Homogentisic acid (2,5-dihydroxyphenylacetic acid, HGA) was isolated and found to be the major antioxidant in the culture supernatant of the SPP-containing medium fermented by Paenibacillus sp. TKU036. Tryptophan was also present in the culture supernatant. The results of high-performance liquid chromatography (HPLC) fingerprinting showed that HGA and tryptophan were produced via fermentation but did not pre-exist in the unfermented SPP-containing medium. Neither HGA nor tryptophan was found in the culture supernatants obtained from the fermentation of nutrient broth or other chitinous material, i.e., medium containing shrimp head powder, by Paenibacillus sp. TKU036. The production of HGA via microorganisms has rarely been reported. In this study, we found that squid pen was a potential carbon and nitrogen source for Paenibacillus sp. Tryptophan (105 mg/L) and HGA (60 mg/L) were recovered from the culture supernatant. The isolated HGA was found to have higher antioxidant activity (IC50 = 6.9 μg/mL) than α-tocopherol (IC50 = 17.6 μg/mL). The anti-inflammatory activity of the isolated HGA (IC50 = 10.14 μg/mL) was lower than that of quercetin (IC50 = 1.14 μg/mL). As a result, squid pen, a fishery processing byproduct, is a valuable material for the production of tryptophan and the antioxidant and anti-inflammatory HGA via microbial conversion.

Biosynthesis of α-Glucosidase Inhibitors by a Newly Isolated Bacterium, Paenibacillus sp. TKU042 and Its Effect on Reducing Plasma Glucose in a Mouse Model

“…Similar phenomena were found in our previous reports, which showed SPP as the most suitable C/N source for the production of exopolysaccharides and antioxidants by isolated strains of Paenibacillus [20,21,22,23]. Three sources of C/N: 1% SPP, 1% shrimp head powder (SHP), and 0.8% nutrient broth (NB), were investigated for the production of aGIs by Paenibacillus sp.…”

Conversion of Shrimp Head Waste for Production of a Thermotolerant, Detergent-Stable, Alkaline Protease by Paenibacillus sp.

“…Paenibacillus is a useful bacterial family employed in the medical, industrial, and agricultural fields [48]. Recently, when fishery processing by-products were used as the nutrition source (carbon and nitrogen), several strains of Paenibacillus exhibited excellent abilities in the production of bioactive compounds, including α-glucosidase inhibitors [49], exopolysaccharides [43], anti-inflammatory medication [50,51], antioxidants [30], and chitosanases [11][12][13]. However, few reports have examined proteases derived from Paenibacillus, especially using shrimp heads.…”

Phytochemical and Biological Investigation of Urtica Urens L. Growing in Egypt

“…In addition to the signals attributable to the 3substituted indole skeleton, 13 CNMR spectra also showed signals for a methylene carbon at δ 27.0 which corresponds to (C-10), methine carbon signal at δ 55.2 which corresponds to (C-11) and carbonyl carbon signal at δ 173.1 which corresponds to (C-12). By comparing m.p., EI-MS, 1 HNMR and 13 CNMR data with previously published data 33,34 , compound 8 was identified as 2amino-3-(1H-indol-3-yl) propanoic acid (tryptophan). This is the first time to be isolated from U. urens L. aerial parts.…”