A novel acidic and low-temperature-active endo-polygalacturonase from Penicillium sp. CGMCC 1669 with potential for application in apple juice clarification

► We cloned a novel endo-PG gene from Penicillium sp. and expressed in Pichia pastoris. ► The enzyme was highly active and stable at acidic pH with pH optimum at 3.5. ► The enzyme had 90% of the activity at 35-55 °C and remained active even at 0 °C. ► Endo-PG I was more efficient in juice clarification than pectin lyase alone. ► These properties make it promising in the fruit juice extraction and clarification.