Efficient biodegradation of malachite green by a newly isolated Klebsiella pneumoniae strain WA‐1

Abstract

Biodegradation by microorganisms is a potential treatment technique of malachite green (MG) in aquaculture environments. In this study, a bacterium with high MG decolorization and biodegradation ability was isolated through enrichment culture and color‐decoloration circle method, and was identified as Klebsiella pneumoniae WA‐1 after molecular and biochemical identification. The MG biodegradation characteristics and the factors affecting the MG biodegradation ability of this strain were studied using KBH4 reduction‐high performance liquid chromatography with fluorescence detector (HPLC‐FLD) method. K. pneumoniae WA‐1 could efficiently biodegrade MG in aqueous solution without any nutrients that over 94.0% MG was biodegraded by this strain at 1–20 mg/L within 0.5 hr and 100% MG were biodegraded at 1–10 mg/L within 12 hr. Fairly stable MG biodegradation performance was observed in complex environments, including various pH, temperature, salinity, and metal ions, especially at low MG concentration. Furthermore, the presence of NaCl, Mn2+, Mg2+, or Cu2+ could enhance the MG biodegradation ability of this strain. These results indicate that K. pneumoniae WA‐1 could be used as a potential MG degradation agent in complex aquaculture environments.

Strategies for Solving the Issue of Malachite Green Residues in Aquatic Products: A Review

“…Even so, the MG degradation efciency of Deinococcus radiodurans was up to 97.2% within 30 min [122], and this strain seems to be the most efcient MG degradation microbe. In some of the published works referenced above, the impacts of environmental factors on the MG degradation activities were investigated, and the degradation conditions were also optimized [104,108]. Furthermore, the degradation products, active enzymes, and related genes for some microbes were identifed, and therefore the possible degradation pathway of MG for these microbes was proposed [105,107].…”

“…Most of the reported MG degradation microbes only show activity in the culture medium. However, the Klebsiella pneumonia WA-1 isolated by Li et al [108] could efciently degrade MG in an aqueous solution without any nutrients, which illustrates the great potential for practical application of this strain. Enzymatic degradation of MG was also widely concerned in recent years.…”

Volatile Flavor Improvement and Spoilage Microorganism Inhibition in Low-Salt Fish Sauce (Yulu) by Salt-Tolerant Bacillus subtilis

“…The salt-tolerant Bacillus subtilis B-2, which was stored in the China General Microbiological Culture Collection Center (CGMCC No. 23784), was maintained on the LB agar slant (10 g/L peptone, 5 g/L yeast extract powder, 10 g/L NaCl, and 18 g/L agar; pH 7.0) at 4 • C. Pre-culture of B. subtilis was performed according to a previous study [13]. Briefly, the strain was first transferred on a fresh YEPD agar slant and incubated at 37 • C for 24 h. Thereafter, a loopful of the slant culture was transferred into 50 mL liquid LB medium (10 g/L peptone, 5 g/L yeast extract powder, and 10 g/L NaCl; pH 7.0) in 250 mL Erlenmeyer flask and was incubated at 37 • C and 180 r/min for 24 h.…”

Adsorption capacity, isotherm, kinetic, and thermodynamic studies on adsorption behavior of malachite green onto natural red clay

“…The other industries are leather, paper, food, hair colorings, and so forth 1,2 . It is estimated that about 2% of the dyes processed in textile dyeing facilities go into wastewater, 3 due to high compositional variability and high color density. The presence of these dyes, released from industrial wastewaters, is a serious problem for all forms of life due to toxicity 4 …”