Factors influencing pigment production by halophilic bacteria and its effect on brine evaporation rates

Abstract

Summary The disposal of reject brine, a highly concentrated waste by‐product generated by various industrial processes, represents a major economic and environmental challenge. The common practice in dealing with the large amounts of brine generated is to dispose of it in a pond and allow it to evaporate. The rate of evaporation is therefore a key factor in the effectiveness of the management of these ponds. The addition of various dyes has previously been used as a method to increase the evaporation rate. In this study, a biological approach, using pigmented halophilic bacteria (as opposed to chemical dyes), was assessed. Two bacteria, an Arthrobacter sp. and a Planococcus sp. were selected due to their ability to increase the evaporation of synthetic brine. When using industrial brine, supplementation of the brine with an iron source was required to maintain the pigment production. Under these conditions, the Planococcus sp. CP 5‐4 produced a carotenoid‐like pigment, which resulted in a 20% increase in the evaporation rate of the brine. Thus, the pigment production capability of halophilic bacteria could potentially be exploited as an effective step in the management of industrial reject brines, analogous to the crystallizer ponds used to mine salt from sea water.

Evaluation of antioxidant potential of pigments extracted from Bacillus spp. and Halomonas spp. isolated from mangrove rhizosphere

“…3A ). According to the data reported in the literature, the characteristic absorbance peaks of carotenoids are between 400 nm and 500 nm (Scott, 2001 ; Khaneja et al, 2009 ; Zaghdoudi et al, 2017 ; Silva-Castro et al, 2019 ). The visible ranges of absorption for the extracted pigments were between 410 nm and 480 nm, which is similar to those described earlier and therefore indicate that these pigments were carotenoids.…”

“…For large-scale production of the pigments, the incubation temperature and salt concentrations in the media were optimized (Silva-Castro et al, 2019 ). All the cultures showed higher growth at 1 and 2.5% salt concentration in the medium with OD 600 of 0.790 for B. infantis (MZ) and 1.383 for Bacillus spp.…”

Structure and biosynthesis of carotenoids produced by a novel Planococcus sp. isolated from South Africa

“…The Planococcus sp. CP5-4 strain used in this study originated from a collection of bacterial cultures previously isolated from brine samples taken from the Cerebos crystallizer salt ponds in Velddrif, Western Cape, South Africa (S 32°47′10,632, E 18°10′9,499) [ 69 ]. Planococcus sp.…”

Bioprospecting Studies of Halophilic Bacteria – Streptomyces sp MA05 and Halobacterium sp MA06

“…Pigment production by Halorubrum sodomense was reported to be maximum at NaCl concentration of 30% [40]. Salt concentration has a direct influence on pigment production [41]. The abundant compound shows maximum peak at retention time of 23.06 and 13.3 (Figure 5), which stands for phenol,2,6-bis(1,1dimethylethyl-).…”