TABLE 2.

Summary of ethanol production by various Kluyveromyces marxianus strains.

Strain name	Substrate	Pretreatment technique	Fermentation condition	Ethanol titer (g/L)	References
Kluyveromices marxianus (Kmx24)	Sweet whey	-	4.50 g/L of precursor, 0.76 g/L of salt, and fermentation duration of 48 h	1.2 (2-phenylethanol)	Alonso-Vargas et al. (2022)
Kluyveromices marxianus JKSG-6	Cotton stalk	Sequential dilute acid–alkali pretreatment using sulfuric acid (1%, v/v) and sodium hydroxide (3%, w/v)	For SSF, flasks were incubated at 42°C. PSSF experiments were conducted by performing a 12-h enzymatic pre-saccharification at 50°C, following temperature reduction to 42°C before yeast inoculation	26.10	Kaushik et al. (2022)
Kluyveromices marxianus MM III-41	Green coconut shell	Hydrothermal	Fermentation was carried out at 37°C for 24 h and 75 rpm	8.83	Gomes et al. (2021)
			Using 100 ml of reaction medium
Kluyveromices marxianus MM III-41	Green coconut shell	Acidic	Fermentation was carried out at 37°C for 24 h and 75 rpm	9.71	Gomes et al. (2021)
			Using 100 ml of reaction medium
Kluyveromices marxianus MM III-41	Coconut-tree leaflet	Hydrothermal	Fermentation was carried out at 37°C for 24 h and 75 rpm	10.26	Gomes et al. (2021)
			Using 100 ml of reaction medium
Kluyveromices marxianus MM III-41	Coconut-tree leaflet	Acidic	Fermentation was carried out at 37°C for 24 h and 75 rpm	7.01	Gomes et al. (2021)
			Using 100 ml of reaction medium
Kluyveromices marxianus MM III-41	Coconut-tree leaf stalk	Hydrothermal	Fermentation was carried out at 37°C for 24 h and 75 rpm	12.99	Gomes et al. (2021)
			Using 100 ml of reaction medium
Kluyveromices marxianus MM III-41	Coconut-tree leaf stalk	Acidic	Fermentation was carried out at 37°C for 24 h and 75 rpm	7.44	Gomes et al. (2021)
			Using 100 ml of reaction medium
Kluyveromyces marxianus DMKU-KS07	Cassava chip hydrolysates and molasses	-	Modified simultaneous saccharification and fermentation with co-fermentation of substrates from the enzymatic hydrolysates of raw cassava chips at 42°C for 12 h	118	Lomthong et al. (2021)
K. marxianus ETP87	Shola dairy	-	Whey fermentation was conducted in a 250-ml flask containing 100 ml crude whey	12.49	Tesfaw et al. (2021)
			The media in the flasks were inoculated with K. marxianus ETP87 seed cultures and allowed to grow aerobically
			Fermentation was carried at 30°C on a water bath shaker at 100 rpm
Kluyveromyces marxianus	Azolla weed hydrolysate	Thermal acid hydrolysis	Ethanol fermentation was conducted with Azolla weed hydrolysate (100 ml) in a 250-ml Erlenmeyer flask under semianerobic conditions	26.8	Chupaza et al. (2021)
			Azolla weed hydrolysates were fermented at 30°C and 150 rpm
Kluyveromyces marxianus	Banana peels	Pretreatment at 121°C for 15 min	Simultaneous saccharification and fermentation (SSF) were executed in 100-ml Erlenmeyer flasks using 10% (w/v) of autoclaved banana peels with 2 g/L yeast at pH 4.8	11	Palacios et al. (2021)
			Assay was performed for 24 h in a rotatory shaker at 150 rpm at 41°C
Kluyveromyces marxianus MTCC 4139	Cassava peel	Alkali-assisted hydrothermal pretreatment	Fermentation media was autoclaved at 110°C for 15 min and 10% (v/v) K. marxianus inoculum was aseptically added to the fermentation medium. The separate hydrolysis and fermentation were carried out at 30 for 72 h at 150 rpm	(0.44 g/g)	Papathoti et al. (2021)
Kluyveromyces marxianus MTCC 4139	Cassava peel	Alkali-assisted hydrothermal pretreatment	Simultaneous saccharification and fermentation was initiated by aseptically adding 10% (v/v) K. marxianus inoculum, following enzymatic solution containing cellulase (10 FPU/g substrate), α-amylase, and glucoamylase (each containing, 450 IU/g substrate)	(0.41 g/g)	Papathoti et al. (2021)
			SSF was performed at 100 rpm, 40°C for 72 h