323
Other metabolites from the genus Penicillium like roquefortin and meleagrin are
also known to have antimicrobial activities. Terrein (Fig. 12.9f) is a small antifungal
polyketide produced by Aspergillus terreus. Terrein was later found to be an inhibitor of breast cancer, with additional activity against pancreatic and liver cancer cell
lines. Terracyclic acid A is a sesquiterpene antifungal isolated from the same species. Brefeldin A is another small molecular weight polyketide with antifungal and
antitumor activities isolated from Penicillium brefeldianum. Gliotoxin is a diketopiperazine alkaloid produced by Aspergillus fumigates with known antifungal and
antimicrobial activities. The ophiobolins are sesterterpenes isolated mainly from the
genus Bipolaris but also produced by Aspergillus, Sarocladium and Drechslera
with antifungal activities.
3-O-methylfunicone (Talaromyces pinophilus), chaetomugilin family of azaphilones (Chaetomium globosum), Xanthocillin X (Dichotomomyces albus, P. chrysogenum), emestrin A (Emericella striata), wortmannin (T. wortmannii),
cytochalanins and chaetoglobosins (Aspergillus spp., zygosporium, etc.), macrophorin A (Talaromyces purpurogenus), botryodiplodin (T. stipitatus) and the atpenins (P. atramentosum) are examples of fungal metabolites that exhibit antifungal
activity along with antitumor activity (Bladt et al. 2013).
12.4.7 Antimicrobials from Other Prokaryotic Sources
Many bacteria other than the major producers discussed above produce antimicrobials. Micromonospora a genus of gram-positive, aerobic, saprophytic bacteria
belonging to Micromonosporacea family are sources of aminoglycoside, macrolide
and other antibiotics normally designated with names ending in ‘–micin’ to differentiate them from antibiotics produced by Streptomyces. These include gentamycin
produced by Micromonospora purpurea, mutamicin and netilmicin produced by
M. inyonensis, everninomicins produced by M. carbonacea, citreamicins produced
by M. citrea, sisomicin produced by M. inositola and rosaramicin from M. Rosaria
and megalomicin produced by M. megalomicea. Teicoplanins and Ramoplanins are
broad-spectrum antibiotics produced by the bacterial genus Actinoplanes.
Uncultured bacteria represent 99% of all microbial diversity and are untapped
bioresources for anitbacterial discovery. Development of methods to culture bacteria in their natural environments based on cultivation in diffusion chambers has
enabled identification of novel antimicrobial from previously uncultured bacteria.
Lassomycin is a highly basic ribosomally encoded cyclic peptide with an unusual
structural fold that only partially resembles that of other lassopeptides. Lassomycin
exhibit potential bactericidal activity against both growing and dormant mycobacteria, including drug-resistant forms of M. tuberculosis, but little activity against
other bacteria or mammalian cells. Lassomycin exerts its antibacterial activity by
uncoupling ATPase from its proteolytic activity (Gavrish et al. 2014). Teixobactin
(Fig. 12.10), a novel antibiotic from a β-proteobacteria provisionally named
12 Antimicrobials from Microbes
Other metabolites from the genus Penicillium like roquefortin and meleagrin are
also known to have antimicrobial activities. Terrein (Fig. 12.9f) is a small antifungal
polyketide produced by Aspergillus terreus. Terrein was later found to be an inhibitor of breast cancer, with additional activity against pancreatic and liver cancer cell
lines. Terracyclic acid A is a sesquiterpene antifungal isolated from the same species. Brefeldin A is another small molecular weight polyketide with antifungal and
antitumor activities isolated from Penicillium brefeldianum. Gliotoxin is a diketopiperazine alkaloid produced by Aspergillus fumigates with known antifungal and
antimicrobial activities. The ophiobolins are sesterterpenes isolated mainly from the
genus Bipolaris but also produced by Aspergillus, Sarocladium and Drechslera
with antifungal activities.
3-O-methylfunicone (Talaromyces pinophilus), chaetomugilin family of azaphilones (Chaetomium globosum), Xanthocillin X (Dichotomomyces albus, P. chrysogenum), emestrin A (Emericella striata), wortmannin (T. wortmannii),
cytochalanins and chaetoglobosins (Aspergillus spp., zygosporium, etc.), macrophorin A (Talaromyces purpurogenus), botryodiplodin (T. stipitatus) and the atpenins (P. atramentosum) are examples of fungal metabolites that exhibit antifungal
activity along with antitumor activity (Bladt et al. 2013).
12.4.7 Antimicrobials from Other Prokaryotic Sources
Many bacteria other than the major producers discussed above produce antimicrobials. Micromonospora a genus of gram-positive, aerobic, saprophytic bacteria
belonging to Micromonosporacea family are sources of aminoglycoside, macrolide
and other antibiotics normally designated with names ending in ‘–micin’ to differentiate them from antibiotics produced by Streptomyces. These include gentamycin
produced by Micromonospora purpurea, mutamicin and netilmicin produced by
M. inyonensis, everninomicins produced by M. carbonacea, citreamicins produced
by M. citrea, sisomicin produced by M. inositola and rosaramicin from M. Rosaria
and megalomicin produced by M. megalomicea. Teicoplanins and Ramoplanins are
broad-spectrum antibiotics produced by the bacterial genus Actinoplanes.
Uncultured bacteria represent 99% of all microbial diversity and are untapped
bioresources for anitbacterial discovery. Development of methods to culture bacteria in their natural environments based on cultivation in diffusion chambers has
enabled identification of novel antimicrobial from previously uncultured bacteria.
Lassomycin is a highly basic ribosomally encoded cyclic peptide with an unusual
structural fold that only partially resembles that of other lassopeptides. Lassomycin
exhibit potential bactericidal activity against both growing and dormant mycobacteria, including drug-resistant forms of M. tuberculosis, but little activity against
other bacteria or mammalian cells. Lassomycin exerts its antibacterial activity by
uncoupling ATPase from its proteolytic activity (Gavrish et al. 2014). Teixobactin
(Fig. 12.10), a novel antibiotic from a β-proteobacteria provisionally named
12 Antimicrobials from Microbes