Table 1.

Genetic tools for biomining microorganisms.

Organism	Acidithiobacillus ferrooxidans	Acidithiobacillus caldus	Sulfolobus spp. (S. acidocaldarius, S. islandicus, S. solfataricus)
DNA delivery	Electroporation [29], Conjugation [30]	Electroporation [31], Conjugation [32]	Electroporation [33]
Shuttle vectors	pTMZ48, pKMZ51 [29], pJRD215 [34], pSDRA1 [35]	pMSD2 [36], pLAtcE [37]	pAG-series [38], pEXS-series [39], pKMSD48 [40], pMJ03 [41], pMSSVderivatives [42], pA-pN [43]
Selection	HgCl2 [29], kanamycin/tetracyline/streptomycin [30,34,35]	Kanamycin/stretomycin [36,37], chloramphenicol acetyltransferase [44]	Hygromycin B [39], Uracil [41,43], lactose [42,43,45]
Markerless gene knockout	Kanamycin mutated allele [46]	Kanamycin mutated allele [47]	Insertion of lacS gene [48,49]
Reporter genes	GusA (β-glucuronidase) [50]	-	lacS (β-galactosidase) [42]
Regulated gene expression	tac promoter [51], cycA1 and tusA promoter [52]	tac promoter [36], tetH promoter [37]	aat promoter [39], tf55α promoter [41], araS promoter [45]
Protein overexpression	Arsenic resistance genes [35], rusticyanin [51], 2-keto decarboxylase, acyl-ACP reductase, aldehyde deformylating decarbonylase [53]	arsABC operon [36],α-ketoglutarate dehydrogenase, succinate dehydrogenase [37]	ABCE1 protein [54], IF2 [55]

ACP: Acyl carrier protein.