Probiotic assessment and antioxidant characterization of Lactobacillus plantarum GXL94 isolated from fermented chili

Abstract

Oxidative stress is caused by an imbalance between prooxidants and antioxidants, which is the cause of various chronic human diseases. Lactic acid bacteria (LAB) have been considered as an effective antioxidant to alleviate oxidative stress in the host. To obtain bacterium resources with good antioxidant properties, in the present study, 113 LAB strains were isolated from 24 spontaneously fermented chili samples and screened by tolerance to hydrogen peroxide (H2O2). Among them, Lactobacillus plantarum GXL94 showed the best antioxidant characteristics and the in vitro antioxidant activities of this strain was evaluated extensively. The results showed that L. plantarum GXL94 can tolerate hydrogen peroxide up to 22 mM, and it could normally grow in MRS with 5 mM H2O2. Its fermentate (fermented supernatant, intact cell and cell-free extract) also had strong reducing capacities and various free radical scavenging capacities. Meanwhile, eight antioxidant-related genes were found to up-regulate with varying degrees under H2O2 challenge. Furthermore, we evaluated the probiotic properties by using in vitro assessment. It was showed that GXL94 could maintain a high survival rate at pH 2.5% or 2% bile salt or 8.0% NaCl, live through simulated gastrointestinal tract (GIT) to colonizing the GIT of host, and also show higher abilities of auto-aggregation and hydrophobicity. Additionally, the usual antibiotic susceptible profile and non-hemolytic activity indicated the safety of the strain. In conclusion, this study demonstrated that L. plantarum GXL94 could be a potential probiotic candidate for producing functional foods with antioxidant properties.

Endophytic bacteria isolated from Urtica dioica L.- preliminary screening for enzyme and polyphenols production

“…Other researchers were able to evaluate the antioxidant capacity of cell-free supernatants as well as we did in our research. Zhou et al [ 74 ] tested cell-free extract of Lactobacillus plantarum GXL94 which exhibited significant capture of ABTS radical activity, with ratio of 89.61%. What is more, they evaluated the post-culture supernatant which has 94.63% of ABTS radical scavenging activity.…”

Probiotic and functional potential of lactic acid bacteria isolated from pulque and evaluation of their safety for food applications

“…Following this, the bacterial culture was centrifuged at 4500 × g for 6 min at 4°C, after which the pellet was subjected to two washes with PBS and adjusted to 10 8 –10 9 CFU/mL. Subsequently, an aliquot of the cell culture was separately inoculated (10%) in gastric juice (PBS with 0.3% pepsin and adjusted to pH 2.0 with HCl) ( Kumari et al, 2022 ; Zhang et al, 2022 ) and in intestinal juice (PBS with 0.3% bile salts, 0.1% pancreatin and adjusted to pH 8.0 with NaOH) ( Zhou et al, 2022 ) and incubated at 37°C for 3 h under microaerophilic conditions. Finally, in the combined treatment, the GJ culture was inoculated at 10% in the IJ (GJ/IJ) and incubated at 37°C for 3 h in microaerophilic conditions ( Zhang et al, 2022 ).…”

Exploring the Preventive and Therapeutic Mechanisms of Probiotics in Chronic Kidney Disease through the Gut–Kidney Axis

“…However, the speed of removal of a toxic compound is strain-specific and affected by the physiological state of the strain, pH, and nutrients . Other selection criteria, including decreasing indole production by Escherichia coli , antipathogenic, , antioxidant, , anti-inflammatory, , and gut barrier protection , are highly recommended to increase the therapeutic potentials for CKD.…”