Degradation of Ficus elastica rubber latex by Aspergillus terreus, Aspergillus flavus and Myceliophthora thermophila

Since isolates recovered on medium containing-Ficus elastica latex showed good growth on the respective natural rubber than those recovered on Euphorbia pulcherrima or Ficus nitida, 16 of these isolates were selected for further growth experiments on natural rubber to determine their protein content as well as rubber viscosity. Of these, the mesophilic strains Aspergillus terreus AUMC 4682, Aspergillus flavus AUMC 4795 and the thermophilic strain Myceliophthora thermophila AUMC 4653 showed low rubber viscosity and high mycelia protein content indicating high biodegradation ability of rubber. The strains were subjected for further analysis. They showed high ability to degrade poly (cis-1, 4-isoprene) rubber fig. The ability was also determined by measuring the increase in protein content of each fungus (mg g−1 dry wt), reduction in molecular weight (g mol−1) and inherent viscosity (dl g−1). Moreover the degradation was characterized by determining aldehyde or keto group by Schiff reagent and observing the growth using scanning electron microscopy (SEM).

► Isolation of mesophilic and thermophilic fungi growing on pure natural rubber latex.
► The isolates were Aspergillus terreus, Aspergillus flavus and Myceliophthora thermophila at 25 and 45 °C.
► They gave higher mycelial protein, lower viscosity values, decreased of Mol. wt.
► In addition to releasing of aldehyde or keto group by using Schiff's reagent.
► Also, observing colonization by using SEM after 15 and 30 days.