Influence of copper solvent extractant on microbial community structure of acidophilic microorganisms

Abstract

The influence of different concentrations of copper solvent extractant ZJ 988 on the growth and activity of acidophilic microorganisms was studied and the microbial community structures were compared by 16S rRNA gene clone library analysis. The total bacteria numbers are reduced when 0.5% (volume fraction) extractant is added. The proportions of Acidithiobacillus ferrooxidans and Acidiphilium organovorum are increased, whereas the proportion of Leptospirillum ferriphilum is reduced. When the concentration of extractant is elevated to 1%, growth of all bacteria is inhibited. Clone library results reveal that the dominant bacteria in the culture solution with/without the extractant are At. ferrooxidans, A. organovorum and L. ferriphilum. The sensitivity order of the three bacteria to the extractant from the most to the least is found to be L. ferriphilum＞At. ferrooxidans＞A. organovorum.

Effect of Different Solvent Extractants on the Activity and Community Structure of Acidophilic Microorganisms

“…ferrooxidans＞A. organovorum [1].When cultured with M5774 and Cyanex 272, the proportion of Acidithiobacillus ferrooxidans was higher than Leptospirillum ferriphilum, while when cultivated with P204 and P507, the number of Leptospirillum ferriphilum was higher. The microbial community of culture contacted with N235 is similar to the innocula, maybe due to the strong inhibition effect.…”

“…In these processes, leaching solution is recycled, so microorganisms was inevitably contacted with extractant. Previously, researchers mainly studied copper extractant LIX 84IC, LIX 984N, LIX 64 and ZJ988 on the growth and activity of acidophiles [1][2][3][4]. But for widely used copper extractant M5774, cobalt extractant Cyanex 272, nickel extractant P507, iron extractant N235 and P204, their effect on the activity and community structure of acidophilic microorganisms were none of knowledge.…”

Bioleaching of Chalcopyrite Waste Rock in the Presence of the Copper Solvent Extractant LIX984N

“…However, in the case of Sulfobacillus thermosulfidooxidans, copper extraction was reduced to about one-third with 50 mg/L SX reagent. Similar work has been done (Mazuelos et al, 1999;Chen et al, 2010;Davis-Belmar et al, 2012;Liu et al, 2015), but it focused only on one species, plus the type and the concentration of the SX reagent applied in these studies are not identical. Consequently, no comparable data show whether those microorganisms have different sensitivity toward one SX reagent and, if so, how high concentration of the SX reagent each species can resist.…”