Polyhydroxyalkanoates (PHAs) from dairy wastewater effluent: bacterial accumulation, structural characterization and physical properties

Chemical and Biological Technologies in Agriculture

Table 1 Maximum PHB content (%) accumulated by C. necator DSM 13513 grown in LB medium supplemented with mixture of VFA_synthetic, VFA_extracted in different cultivation conditions

Operating mode	Carbon source and aeration conditions		PHB content^a (%)	Time (h)
^bBatch culture	VFA_synthetic	Under shaken in aerobic condition	0.31 ± 0.001^E	24
	VFA_extracted	Under shaken in aerobic condition	0.48 ± 0.006^D	48
	Without VFA	Under shaken in aerobic condition	0.025 ± 0.002^F	24
^cFed-batch fermentation	VFA_synthetic	No aeration	0.81 ± 0.07^B	48
		Aeration	0.60 ± 0.01^C	48
		12 h of aeration	1.34 ± 0.02^A	48
	VFA_extracted	12 h of aeration	0.52 ± 0.03^CD	48

^a The values represent the means ± SD of three replicates. Different letters indicate significant differences (P < 0.05)
^bLB medium (600 mL) with 2% (v/v) of VFA_synthetic, VFA_extracted or without VFA (control). Incubation at 30 °C for 24 or 48 h under shaken in aerobic condition at 200 rpm
^cLB medium (4 L) with 2% (v/v) of VFA_synthetic or VFA_extracted. pH at 6.5. Incubation at 30 °C for 48 h with agitation speed set at 200 rpm. Feeding at 2% (v/v) added at 3, 6, 9 and 12 h. Aeration: air sparging at 1 vvm; 12 h of aeration: air sparging at 1 vvm for 12 h followed by no aeration; no aeration