RT Journal Article SR Electronic(1) A1 Roncal, T. A1 Ugalde, U. O. A1 Barnes, J. A1 Pitt, D.YR 1991 T1 Production of protoplasts of Penicillium cyclopium with improved viability and functional properties JF Microbiology, VO 137 IS 7 SP 1647 OP 1651 DO https://doi.org/10.1099/00221287-137-7-1647 PB Microbiology Society, SN 1465-2080, AB Summary: A new simple procedure for the production of protoplasts of Penicillium cyclopium with high regeneration rates and efficient transport activity is described, involving the use of a preparation of Novozym 234 with very low protease activity. The combination of a heat pretreatment at 55 °C for 15 min with the use of the protease inhibitor aprotinin resulted in a 97% reduction of Novozym 234 protease activity with respect to untreated controls. Polysaccharide-hydrolysing activity was inhibited much less, to 60% of the untreated Novozym 234 level. Protoplasts could be successfully produced with the new low-protease Novozym 234 preparation, showing a threefold increase in regeneration capacity compared to control protoplasts obtained with the original preparation. The rates of 3-O-methylglucose uptake and the capacity to accumulate this sugar analogue were also higher in protoplasts obtained by the new method., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-137-7-1647