Micrographs of the biocatalysts (after washing with deionized
water and drying for 24 h at 60 ◦C) were obtained by scanning electron
microscopy (SEM) using a Leica Cambridge S360 microscope.
To be examined,the dried samples were fixed on a specimen holder
with aluminum tape and then sputtered with gold in a sputtercoater
under high vacuum condition. Each sample was examined
at 700-fold magnification.