I'm not sure if i understand your question clearly. So my answer would be : if you want to get pure culture of certain type of fungi, you need to use isolation such as pour plate or spread plate techniques. Try to get the desire spore as much as you can then pour or spread to PDA plate. Once it start to grow then pick up the colony that you are sure is what you want. Then re spread to PDA or inoculate to other broth media to propagate the culture.

 For your PDA, you may add some antibiotic such as chloramphenicol to inhibit the growth of bacteria.

Best.

sorry you are not getting my question . iam isolating marine fungi from mangrove twigs samples

Do you want to isolate fungi from the surface or from the core of twigs? Are the twigs live or decayed?

The isolation method as well as appropriate growth medium vary greatly in various cases.

I want to isolate fungi from superficial as well as from immersed parts of decaying twigs only.Iam isolating fungi using single spore isolation. is there any methods similar to that and which media to be used for growth

What water salinity is in the  original environment?

Are you studiyng biodiversity of fungi or trying to isolate only one  particular species?

You should use special saline medium , not standard pda. And surely try several media. SSI is OK in your case. Another way is successional dilution of suspension washed from the twig surface or from the mix of colonies obtained from the core of surface sterilized twig placed on agar medium.

I can type you some more details later if you answer my questions .

Regards

can u send me ur email id i will send details

Dear Devadatha,

If we are doing single spore isolation, germinating spores should individually transfer onto fresh petri dishes (PDA or MEA). It is better to have 2-3 replicates from each.

And to reduce the contaminations, we can apply Amoxicillin trihydrate like anti bacterial chemicals. It should mix with PDA or MEA when media temperature is lower than 60 degrees of Celsius.

If you can control moisture content, it is better to keep low RH and it will facilitate fungal growth over bacterial growth.

After a day or two, using a sterile needle under a stereomicroscope we can break the tip of the mycelium and have to transfer to another media. Likewise when we transfer few times we can get a fast growing mycelium from each culture. And it will grow over bacterial growth.

thank u  for ur suggestions 

Low pH can supress growth of some fungal species. Many of marine fungi grow faster under neutral or alkaline pH. So I don't think that acidic conditions is a good way to investigate biodiversity of maribe fungi. You might miss some interesting fungi relative to tgat isolated from solonchaks (saline soils).

iam not providing acidic conditions

Single-spore isolation means just what it says. A single spore is transferred to a single other Petri plate to make sure the colony derived from it is of pure genetics and not a mixture of genetics from multiple spores. This can be achieved by applying a pure spore suspension of the fungus desired (to the isolation plate) that is sufficiently diluted to allow well separation of spores so that when some of them germinate, a single germinating spore can be transferred with a very fine needle to cut out a very small amount of agar around the germinating spore to transfer it. Select germinating spores that have a relatively short hypha so that the amount of agar transferred is quite small.  This work requires a stereoscope with 20x to 60x magnification depending on spore size. Single-spore cultures are not derived from hyphal tips as some have said in response to your question.

obviously i agree with your answer. but while we transfers single germinating spore there may be chance of other spores , it s very difficult to transfer single spore . i used to do in stereozoomic microscope only . thank you a lot for your detailed suggestions