11.5.2 Amylase Inhibitors Produced by Marine
Actinomycetes
A. The Search for Amylase Inhibitor-Producing Bacteria
Amylase inhibitors are relatively rare substances. Because they block amylase
activity and specifically inhibit the digestion and absorption of starch, they have
potential applications in antiobesity (diet) and other medications. Several inhibitors
have been isolated and purified to date from land-based plants and actinomycetes.
Amylase inhibitors are known to fall into two major categories: plant-derived
high-molecular weight protein substances and actinomycetes-derived low-molecular
weight glycoside substances. To date, however, little research has reported the production of these substances from marine microorganisms.
In a study of amylase inhibitor productivity for around 5000 strains of marine
microorganisms isolated from seawater, Imada found actinomycetes in sea-floor
sediment that produced such an inhibitor. As seen in Fig. 11.10, when grown in an
agar medium with starch, these actinomycetes inhibit the activity of amalyse added
after culturing, resulting in a purple halo (urea-starch reaction) due to production of
the inhibitor around the colony. As a result, producing and non-producing bacteria
can be easily distinguished.
Figure 11.8 shows the average physical changes observed in around ten healthy
male and female subjects who consumed 10 mg of the wheat-derived amylase
inhibitor A1 with every meal for a month, with no constraints on eating or physical
activity. Clear weight decreases were observed for both men and women with A1
construction, suggesting possible applications in antiobesity medications
(Murao et al. 1977; Imada 2009).
Fig. 11.8 Changes in body weight for human subjects consuming a wheat-derived amylase
inhibitor (AI) with an exercise regimen
408
11 Marine Microorganism Resources and Biotechnology
Actinomycetes
A. The Search for Amylase Inhibitor-Producing Bacteria
Amylase inhibitors are relatively rare substances. Because they block amylase
activity and specifically inhibit the digestion and absorption of starch, they have
potential applications in antiobesity (diet) and other medications. Several inhibitors
have been isolated and purified to date from land-based plants and actinomycetes.
Amylase inhibitors are known to fall into two major categories: plant-derived
high-molecular weight protein substances and actinomycetes-derived low-molecular
weight glycoside substances. To date, however, little research has reported the production of these substances from marine microorganisms.
In a study of amylase inhibitor productivity for around 5000 strains of marine
microorganisms isolated from seawater, Imada found actinomycetes in sea-floor
sediment that produced such an inhibitor. As seen in Fig. 11.10, when grown in an
agar medium with starch, these actinomycetes inhibit the activity of amalyse added
after culturing, resulting in a purple halo (urea-starch reaction) due to production of
the inhibitor around the colony. As a result, producing and non-producing bacteria
can be easily distinguished.
Figure 11.8 shows the average physical changes observed in around ten healthy
male and female subjects who consumed 10 mg of the wheat-derived amylase
inhibitor A1 with every meal for a month, with no constraints on eating or physical
activity. Clear weight decreases were observed for both men and women with A1
construction, suggesting possible applications in antiobesity medications
(Murao et al. 1977; Imada 2009).
Fig. 11.8 Changes in body weight for human subjects consuming a wheat-derived amylase
inhibitor (AI) with an exercise regimen
408
11 Marine Microorganism Resources and Biotechnology