Antibacterial activity in microalgae cultures

Abstract

Five cultures of microalgae (Chlorella minutissima, Tetraselmis chui, Nannochloropsis sp., Arthrospira platensis and Isochrysis sp.) with no culturable bacteria were tested for their ability to inhibit the growth of six Vibrio bacterial strains (V. parahaemolyticus, V. anguillarum, V. splendidus, V. scophthalmi, V. alginolyticus and V. lentus). The influence of light on the antibacterial activity of the microalgae was investigated. All microalgae cultures inhibited the growth of bacteria compared with the control treatments (P < 0.05), and their antibacterial activity was not influenced by the presence or absence of light. In the control groups, the numbers of bacteria increased exponentially during the experimental period in the absence of microalgae cells demonstrating that the bacterial cells were able to utilize the growth medium of microalgae cultures. The present results may explain the low levels or absence of Vibrio strains in microalgae cultures, and the positive effect of addition of microalgae in rearing of fish larvae, and implicate the production of antibacterial compounds by microalgae cells.

Changes in phytochemical content and pharmacological activities of three Chlorella strains grown in different nitrogen conditions

“…Chlorella species have high antimicrobial activity (Ördög et al 2004;Ghasemi et al 2007;Kokou et al 2012) as was found in the present study where noteworthy MIC (<1 mg mL −1 ) values were recorded in about 80 % of the tested extracts. While studies evaluating the potential of different type of microalgae are well documented (Ördög et al 2004;Bhagavathy et al 2011;Nair and Krishika 2011;Prakash et al 2011;Kokou et al 2012), attempts to manipulate the antimicrobial activity based on the culture conditions are limited (Noaman et al 2004;Abedin and Taha 2008;Aremu et al 2014). The current study highlights the potential of manipulating the N concentration and cultivation time to increase the antimicrobial activity of three Chlorella strains as antimicrobial activity generally varied over time relative to the N content in the cultures.…”

“…Furthermore, the effect of different stress factors on some biochemical changes in semi-continuous batch cultures of Chlorella minutissima grown in nitrogen (N)-deficient conditions have been highlighted (Ördög et al 2012). Even though the pharmacological potential of Chlorella has been well-documented (Amaro et al 2011;Kokou et al 2012;Shanab et al 2012), there is no evidence of how the manipulation of the growth conditions influence the phytochemical and biological activities. Hence, the current study focused on the effect of N concentration and culture age (5 and 10 days in culture) on the phytochemical (phenolic, flavonoid, condensed tannin, and iridoid) content and pharmacological (antioxidant, acetylcholinesterase inhibitory [AChEI], and antimicrobial) activities of three Chlorella strains.…”

Green water technology for the production of pacific white shrimp, Penaeus vannamei (Boone, 1931)

“…A study reports that when green water-shrimp growout method was applied, outbreak of luminous vibriosis could be prevented in tiger shrimp culture ponds (Rosa, 2004;Corre et al, 2005;Jimenez et al, 2016). The mechanism behind the beneficial effect of green water includes the algal production of antibacterial substances as well as production of compounds that inhibit virulence gene regulation for e.g., quorum sensing inhibitors (Natrah et al, 2011;Kokou et al, 2012). Therefore, it is evident that the green water had the ability to control harmful Vibrio population in the pond and this can be attributed as a reason for the enhanced survival rate recorded in treatment ponds.…”

“…Several mechanisms have been linked to the beneficial effect of green water, including the production of antibacterial substances by algae (Kokou et al, 2012) and compounds that inhibit virulence gene (Natrah et al, 2011;. Considering the significance of green water, a study was conducted to test the efficacy of green water from a fish culture pond on the growth, health status and production of Pacific white shrimp, Penaeus vannamei (Boone, 1931) an ideal candidate species for coastal aquaculture.…”

Pharmaceutically Valuable Bioactive Compounds of Algae

“…There is ample experimental evidence of its antitumor, anticoagulant, antibacterial, antioxidant, and antihyperlipidemia effects in addition to a hepatoprotective property and the immune-stimulatory activity of enzymatic protein hydrolyzate [30][31][32][33][34]. Many antioxidant compounds are thought to be responsible for Chlorella functional activities.…”