Anionic lipopeptides from Bacillus mojavensis I4 as effective antihypertensive agents: Production, characterization, and identification

Abstract

A new isolated Bacillus mojavensis strain I4 was found as producer of biosurfactants by different screening methods, such as parafilm M test, hemolytic activity, oil displacement test, emulsification index, surface tension, and lipase production assay. Enhanced biosurfactants production was obtained using glucose and glutamic acid as carbon and nitrogen sources, respectively. The optimal production of the biosurfactants was obtained by using a C/N ratio of 17, pH of 7.0, and temperature of 37°C. The surface tension was reduced to 29 mN/m and the emulsification index E24 of 62% was achieved after 72 h of culture. The purified biosurfactants showed stability with regard to surface tension reduction and emulsification in a wide range of temperatures (4–120°C), pH (4–10), and salinity (2–12% of NaCl). The thin‐layer chromatography showed that the produced biosurfactants were lipopeptides. The biosurfactants were characterized as a group of anionic lipopeptides with zeta potential measurement. Chromatographic characterization using HPLC revealed that I4 lipopeptides contained numerous isoforms and surfactin was the major component. Moreover, the I4 lipopeptides showed interesting angiotensin‐converting enzyme‐inhibitory activity.

Antibacterial, anti-adherent and cytotoxic activities of surfactin(s) from a lipolytic strain Bacillus safensis F4

“…Surface tension is a key parameter for the evaluation of biosurfactant production.In fact, a microorganism is considered as a promising biosurfactant producer, if it could reduce the surface tension to less than 40 mN m -1 (Shete et al, 2006). The obtained results showed that our biosurfactant is able to reduce surface tension until 30.73mN m -1 ± 0.48 which is lower than results obtained by Ghazala et al(2017) during the characterization of an anionic lipopeptide produced by Bacillus mojavensis I4 where the surface tension of the culture supernatant was 31.5 ± 0.8mN m -1 .Moreover, our results are very close to those obtained by Jemil et al, (2016) which showed that the best result in decreasing surface tension was observed with Bacillus methylotrophicusDCS1 strain (31 mN m -1 ).Likewise, other study showed that biosurfactants produced by O.anthropi HM-1 and C.freundii HM-2 were able to reduce surface tension until 30.8 ± 0.6 and 32.5 ± 1.3 mNm -1 , respectively (Ibrahim 2018). While, compared to surface tensions of some chemical surfactants studied by Ghazala et al (2017), B.safensisF4 cell free broth showed lower surface tension than SDS (34.8±1.3mN m -1 ) and Triton X-100 (32±0.9mN m -1 ).…”

Valorization of Date Syrup by the Production of Lipopeptide Biosurfactants by a Bacillus mojavensis BI2 strain: Bioprocess Optimization by Response Surface Methodology and Study of Surface Activities

“…For the dispersant activity of motor oil, slight activations are observed at concentrations ranging from 0.5 to 4% NaCl. These results are similar to numerous previous work reporting the stability of the surface activities of biological surfactants after pre-incubation in the presence of decreasing NaCl concentration (Chen et al 2017, Feng et al 2019, Ghazala et al 2017, Kiran et al 2017, Martins et al 2018, Purwasena et al 2019, Qiao &Shao 2010). This offers a broad spectrum of application of BI2 biosurfactant in the bioremediation of saline and sea waters contaminated by hydrocarbons.…”

“…In particular, there is an improvement in the dispersant activity of the oil for heat treatments ranging from 60 to 90°C. Similarly, numerous previous studies reported the stability of the surface activity of lipopeptide biosurfactants (Chen et al 2017, Feng et al 2019, Ghazala et al 2017, Kiran et al 2017, Martins et al 2018, Purwasena et al 2019, Qiao &Shao 2010. As observed in Fig.…”

“…Generally, lipopeptides can be produced using a wide range of carbohydrate-like hydrophilic carbon substrates and hydrophobic substrates separately or on the two substrates at the same time (Mnif &Ghribi 2015b). Biosurfactants can be produced using a wide range of carbohydrate-like hydrophilic carbon substrates (Zhang et al 2016); (Ghazala et al 2017); (Hmidet et al 2017); (Phulpoto et al 2020) or hydrophobic substrates such as vegetable oils and hydrocarbons (Ndlovu et al 2017); (Ohadi et al 2017); (Patowary et al 2017) and this either as the sole source of carbon or in combination (Sarubbo et al 2016); (Joy et al 2017). However, glucose remains the primary source for the production of biosurfactants (Eswari et al 2016).…”

COVID-19: Eco-friendly hand hygiene for human and environmental safety

“…Rhamnolipids, sophorolipids, and surfactin are the most widely studied microbial biosurfactants. Their antimicrobial (antibacterial and antifungal), pharmaceutical and medical applications such as anticancer, anti-inflammatory and immunomodulators, antihypertensive activities are well reported in the literature [ 30 , 6 , 29 , 31 ]. More importantly, they have also been active against various viruses.…”