Hi Lorenza,

You can take a look to my papers. If you need some details. I'm here for answers.

Regards

Hi Lorenza,

From my experience I can say that waste water is a very difficult matrix for DNA isolation. Although, you can use filtration, as suggested by Dr Lucia, but by using a particlular pore size filter, you may lose organisms smaller than the pores. Such as if you are using a 0.45u filter, you may be able to retain majority of the bacteria and cells larger than that, but then you will loose viruses (especially phages), which are an important constituents of waste water. Centrifugation at different speed will also  cause loss of different group of organisms. 

We thus take 20 ml of waste water samples, treat it overnight with final 1% SDS and 25ug/mL of ProteinaseK at 55 degrees centrigrade, followed by Phenol Chloroform extraction (at least 2 times) followed by extraction with Chloroform:Isoamyl Alcohol (24:1), followled by ethanol precipitation and alcohol washing (75%). we generally reconstitute the pellets in 500 ul- 1000 ul of Tris buffer, check the quantity and quality on agarose gels. Usually a light smear starting from a heavy band of more than 10Kb is expected. We further take an aliquot of this total DNA (usually 200 ul) and repurify it using soil/ stool DNA kit (these kits are optimized for removing heavy amounts of enzyme inhibitors from the samples). This way you can get purified total DNA from waste water, which is good for down stream applications such as PCR and NGS.

Hope this works for you too. Please let me know, if it works.

Best wishes

SD

In my opinion, it will depend to DNA you want to extract from wastewater; Viral, fungi, bactaria, parasitis ?

We are interested in microbial communities, especially algae, cyanobacteria, bacteria and fungi. We want to understand how these communities change during the year and in different years.