[Sources of dissolved organic carbon and the bioavailability of dissolved carbohydrates in the tributaries of Lake Taihu].
Surface water samples of Yincungang and Chendonggang Rivers were collected from September 2012 to August 2013 in Lake Taihu. Water temperature, Chlorophyll a and bacterial abundance were analyzed, as well as dissolved organic carbon (DOC) concentrations, stable carbon isotope of DOC (Δ13C(DOC)), specific UV absorbance (SUVA254 ) and dissolved carbohydrates concentrations. Δ13C(DOC) ranged from -27.03% per thousand ± 0.30% per thousand to -23.38%per thousand ± 0.20% per thousand, indicating a terrestrial source. Both the autochthonous and allochthonous sources contributed to the carbohydrates pool in the tributaries. Significant differences in PCHO (polysaccharides) and MCHO (monosaccharides) concentrations were observed between spring-summer and autumn-winter (P < 0.01, n = 12; P < 0.01, n = 12), which might be caused by the variation in the sources and bioavailability of carbohydrates. PCHO contributed a major fraction to TCHO (total dissolved carbohydrates) in autumn and winter, which could be explained by the accumulation of undegradable PCHO limited by the low water temperature; MCHO contributed a major fraction to TCHO in spring and summer, which might be caused by the transformation from PCHO by microbes at high water temperature.
Lin-Lin
LL
Ye
Xiao-Dong
XD
Wu
Fan-Xiang
FX
Kong
Bo
B
Liu
De-Zhi
DZ
Yan
D001682:Biological Availability; D002241:Carbohydrates / Q000032:analysis*; D002244:Carbon / Q000032:analysis*; D002247:Carbon Isotopes / Q000032:analysis; D002681:China; D060106:Lakes; D045483:Rivers / Q000737:chemistry*; D012621:Seasons
D002241:Carbohydrates; D002247:Carbon Isotopes; D002244:Carbon