Beta-glucan production by Botryosphaeria rhodina in different bench-top bioreactors.
OBJECTIVE
Evaluation of the technical feasibility of transferring beta-glucan production by Botryosphaeria rhodina DABAC-P82 from shaken flasks to bench-top bioreactors.


RESULTS
Three different bioreactors were used: 3 l stirred tank reactor (STR-1) equipped with two different six-blade turbines; STR as above but equipped with a three-blade marine propeller plus draft-tube (STR-2); 2 l air-lift column reactor (ALR) equipped with an external loop. STR-1, tested at three different stirrer speeds (300, 500 and 700 rev min(-1)) appeared to be less suitable for beta-glucan production by the fungus, being maximum production (19.4 g l(-1)), productivity (0.42 g l(-1) h(-1)) and yield (0.48 g g(-1) of glucose consumed) markedly lower than those obtained in shaken culture (29.7 g l(-1), 1.23 g l(-1) h(-1) and 0.61 g g(-1), respectively). Better performances were obtained with both STR-2 and ALR. With the latter, in particular, the increase of production was accompanied by reduced fermentation time (25.7 g l(-1) after only 22 h); productivity and yield were highest (1.17 g l(-1) h(-1) and 0.62 g g(-1) of glucose consumed, respectively).


CONCLUSIONS
Using an air-lift reactor with external loop, the scaling up from shaken flasks to bench-top bioreactor of the beta-glucan production by B. rhodina DABAC-P82 is technically feasible.


CONCLUSIONS
Although culture conditions are still to be optimized, the results obtained using the ARL are highly promising.
Selbmann
L
L
Dipartimento di Scienze Ambientali, University of Tuscia, Piazza dell'Università, Viterbo, Italy.
Crognale
S
S
Petruccioli
M
M
D001203:Ascomycota / Q000254:growth & development / Q000378:metabolism*; D018533:Biomass; D019149:Bioreactors; D003470:Culture Media; D005285:Fermentation; D005936:Glucans / Q000096:biosynthesis*; D005947:Glucose / Q000378:metabolism; D003904:Mitosporic Fungi; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*; D013997:Time Factors
D003470:Culture Media; D005936:Glucans; D011135:Polysaccharides, Bacterial; D005947:Glucose