USE OF A MICROSCOPE PHOTOMETER TO ANALYZE IN-VIVO FLUORESCENCE INTENSITY OF EPILITHIC MICROALGAE GROWN ON ARTIFICIAL SUBSTRATA

Citation
G. Becker et al., USE OF A MICROSCOPE PHOTOMETER TO ANALYZE IN-VIVO FLUORESCENCE INTENSITY OF EPILITHIC MICROALGAE GROWN ON ARTIFICIAL SUBSTRATA, Applied and environmental microbiology, 63(4), 1997, pp. 1318-1325
Citations number
55
Categorie Soggetti
Microbiology,"Biothechnology & Applied Migrobiology
ISSN journal
00992240
Volume
63
Issue
4
Year of publication
1997
Pages
1318 - 1325
Database
ISI
SICI code
0099-2240(1997)63:4<1318:UOAMPT>2.0.ZU;2-5
Abstract
An epifluorescence microscope photometer was used to develop a new in vivo fluorimetric method for analyzing fluorescence intensities of epi lithic microalgae grown on clay tiles in the field, This enabled a non destructive, direct quantification of algal biomass on the substratum surface, Measurements of a chlorophyll a standard in ethanol (90%) wit h our fluorimetric method (exitation at 546 nm; emission, >590 nm) cor related well with those from conventional spectrofluorimetric and spec trophotometric methods, Biofilms were analyzed with the microscope pho tometer by measuring the in vivo fluorescence intensity of 70 spots di stributed randomly over the tile surface, They were then analyzed by t he two in vitro methods after photopigment extraction, Chlorophyll a c ontent and in vivo fluorescence intensity correlated well, The regress ion curves were linear up to 6 mu g cm(-2) but were quadratic or hyper bolic at higher concentrations of up to 28 mu g cm(-2) The degree of s catter among individual measurements was higher in biofilms than chlor ophyll a standards, This in vivo analysis is well suited to ecological experiments and has the advantage of measuring on an extremely small scale, which enables direct analysis of the microdistribution of epili thic microalgae in live biofilms, We demonstrated this by comparing fl uorescence intensities of the grazing tracks of the snail Ancylus flav iatilis with those of ungrazed areas, Our in vivo analysis is also uni que in enabling biofilms on artificial substrata to be removed, analyz ed, and then returned intact in field or laboratory experiments.