Table 1.

Overview of fermentation strategies involved in this review

Code	Strategies	Cultivation scale	Process	Time (h)	Production	References
1	Using antifoaming agent	5 l	Fed-batch	260	240 g/l	Bazsefidpar et al. [76]
		5 l	Fed-batch	120	70.56 g/l	Zhu et al. [16]
		50 l	Batch	100	38.3 g/l	Sha et al. [78]
2	Fermentation in weak acid condition	2 l	Batch	217	42.1 g/l	Sodagari et al. [11]
3	Foam fractionation fermentation	2.5 l	Batch	16	0.85 g	Beuker et al. [85]
		2.5 l	Batch	30	3.99 g/l (in foam)	Willenbacher et al. [84]
		10 l	Batch	Ahout 500	70 g	Heyd et al. [80]
4	Foam adsorption fermentation	1.5 l	Batch	42	42 g/l	Zheng et al. [82]
5	Fermentation-defoaming tandem system	10 l fermenter with a 100 l foam collector	Batch	72	30 g/l	Long et al. [10]
		300 l fermenter with a 300 l foam collector	Batch	168	60 g/l	Gong et al. [23]
		2.5 l fermenter with a 0.5 l foam collector	Fed-batch	240	8.06 g/l	Salwa et al. [87]
6	Using Stop valve as a foam breaker	10 l fermenter with a 10 l foam collector	Batch	96	About 40 g/l	Long et al. [75]
7	Solidstate fermentation	30 l air pressure pulsation solid-state fermentation fermenter	Batch	168	39.8 g/l	Gong et al. [19]
		250 ml Erlenmeyer flasks	Batch	144	41.87 g/l	El-Housseiny et al. [101]
		250 ml Erlenmeyer flasks	Batch	288	45.4 g/l	Camilios-Neto et al. [61]
		250 ml Erlenmeyer flasks	Batch	288	46 g/l	Neto et al. [93]
8	Semi-solid-state fermentation	250- ml Erlenmeyer flask	Batch	288	18.7 g/l	Wu et al. [95]
9	Anaerobic fermentation	6 l	Batch	214	0.63 g/l	Zhao et al. [97]
		6 l	Batch	220	1.08 g/l	Zhao et al. [42]
		6 l	Batch	240	1.61 g/l	Zhao et al. [98]
		The extracapillary space of the hollow-fiber setup	Circulate medium in the extracapillary space	1250	About 5 g/l	Pinzon et al. [100]