Characterization of heavy metals resistant heterotrophic bacteria from soils in the Windmill Islands region, Wilkes Land, East Antarctica

Abstract

Abstract:In this study, selected heavy metals resistant heterotrophic bacteria isolated from soil samples at the Windmill Islands region, Wilkes Land (East Antarctica), were character− ized. Phylogenetic analysis revealed affiliation of isolates to genera Bacillus, Lysini− bacillus, Micrococcus and Stenotrophomonas. The strains were found to be psychrotolerant and halotolerant, able to tolerate up to 10% NaCl in the growth medium. The Minimum In− hibitory Concentration of the seven heavy metals Cr, Cu, Ni, Co, Cd, Zn, and Pb was deter− mined in solid media for each bacterial strain. Gram−positive Vi−2 strain and Gram−negative Vi−4 strain showed highest multiply heavy metals resistance, and Vi−3 and Vi−4 strains showed multi−antibiotic resistance to more than a half of the 13 used antibiotics. Plasmids were detected only in Gram−negative Vi−4 strain. The bacteria were able to produce differ− ent hydrolytic enzymes including industrially important proteases, xylanases, cellulases, and b−glucosidases. High heavy metals resistance of the Antarctic bacteria suggests their potential application for wastewater treatment in cold and temperate climates. Highly sensi− tive to Cd and Co ions Vi−1, Vi−5 and Vi−7 strains would be promising for developing biosensors to detect these most toxic heavy metals in environmental samples.

Insight into heavy metal resistome of soil psychrotolerant bacteria originating from King George Island (Antarctica)

“…Moreover, in 162 strains co-resistance (i.e., joint resistance to at least two toxic ions) phenotypes were revealed, which indicates that this phenomenon is not restricted to bacteria originating from the heavily contaminated regions. This high number of heavy metal-resistant bacteria in the Antarctic region may be surprising; however, it is in agreement with the results of other studies (De Souza et al 2006Tomova et al 2014Tomova et al , 2015. Moreover, the high incidence of resistance to heavy metals suggests that bacteria are able to cope and/or adapt to the occurrence of "pollutants" even in low humanimpacted environments (Lo Giudice et al 2013).…”

“…Studies of extreme, polar environments characterized by a still limited anthropogenic influence (e.g., High Arctic or Antarctica) are of great importance, as they may reveal novel genes encoding heavy metal-resistance and metabolism mechanisms, and show the role of naturally occurring microorganisms in biogeochemical cycles. The results of several studies revealed that bacteria isolated from various Arctic and Antarctic environments show resistances to various toxic, antimicrobial agents, such as antibiotics and heavy metals (De Souza et al 2006Lo Giudice et al 2013;Mangano et al 2014;Moller et al 2014;Tomova et al 2014;Perron et al 2015;Rahman et al 2015;Tomova et al 2015;González-Aravena et al 2016;Rodriguez-Rojas et al 2016). However, overall knowledge on the resistome of polar bacteria is still rather limited, and the lack of a systematic approach, combining chemical, microbiological, and molecular analyses, is apparent.…”

Isolation and characterization of Antarctic psychrotrophStreptomycessp. strain INACH3013

“…Antibiotic resistance of psychrotrophic Antarctic bacteria isolated from terrestrial and aquatic samples has been reported by several research groups (De Souza et al 2006, Wong et al 2011, Tomova et al 2014a. Strain INACH3013 was resistant to nine antibiotics, of which four were β-lactam antibiotics and the other five belonged to different antibiotic groups (metronidazole, mupirocin, nitrofurantoin, sulphonamide compounds and trimethoprim).…”

“…2011, Tomova et al . 2014a). Strain INACH3013 was resistant to nine antibiotics, of which four were β-lactam antibiotics and the other five belonged to different antibiotic groups (metronidazole, mupirocin, nitrofurantoin, sulphonamide compounds and trimethoprim).…”

Recovery of metallo-tolerant and antibiotic resistant psychrophilic bacteria from Siachen glacier, Pakistan

“…Siachen glacier is known as the world’s highest non-polar glacier and considered as the highest and world’s biggest garbage dump, 40% of which are plastics and metals, worn out gun barrels, splinters from gun shelling, empty fuel barrels and burnt shelters, which permanently pollute glacial ice and water and leach toxins like cobalt, cadmium, chromium and other metals due to unavailability of natural biodegrading agents [ 60 ]. The heavy metal tolerance could possibly be due to these pollutants, and could possibly lead to antibiotic resistance too, as metal and antibiotic resistance is often present as co-resistance [ 61 ].…”