What types of bacteria grow in kitchen sinks and what do they look like in a culture?

Answer 1

As the centerpiece of the kitchen, it might surprise you that the average kitchen sink contains the most concentrated combination of harmful microorganisms in the entire house. Because raw foods containing microbes are often times placed in the sink, kitchen sinks tend to have higher counts of Escherichia Coli (E. Coli).♥

How they look? Look at the pictures in these links:
http://fig.cox.miami.edu/~cmallery/150/proceuc/c27x9cultures.jpg
http://www.lpsi.barc.usda.gov/emsl/images/petri.jpg