Concerns about feasibility

separability

settleability

efficiency once hampered studies on polyhydroxyalkanoates (PHAs) production

which mainly focused on single strain microorganism or activated sludge rather than artificial microbial consortia. Here

a medium chain length PHAs (mcl-PHAs) producing

Pseudomonas-Saccharomyces

consortium with xylose as the main substrate was studied. Mcl-PHAs accumulation increased from 12.69 mg·L

-1

to 152.3 mg·L

-1

without any optimization method. The presence of

Saccharomyces cerevisiae

though in a relatively low concentration

improved the sedimentation of cell mass of the mixed culture by 60%. Reasons for better sedimentation of the consortium were complex:first

the length of

Pseudomonas putida

increased two to three times in the consortium; second

the positive surface charge of

P. putida

was neutralized by

S. cerevisiae

; third

the adhesion proteins on the surface of

S. cerevisiae

interacted with the

P. putida

.