  We have studied a sample of completely isolated galaxies by means of
long-slit spectroscopy at the 6-m telescope. We have found that 7 of 12 (58 +/-
14 %) galaxies have revealed a presence of large-scale ionized-gas component
which angular momentum is mostly differ from stellar one: 5 of 7 (71 +/- 17 %)
show a visible counterrottation. The diagnostic diagram demonstrates a wide
range of gas excitation mechanism. We have estimated the gas oxygen abundance
in the cases where excitation mechanism by young stars dominates and have found
that ionized gas has a subsolar metallicity. We concluded that cold-gas
accretion from primordial cosmological filaments is unlikely for these objects,
while external accretion from dwarf gas-rich satellites is more suitable.
