One, 'called' (tutaj uzylabym slowa 'termed') biochemical takes place in aeration tanks.
In the first stage the decisive role IS played by activated sludge, which is a consortium of many microorganisms(,) (nie rozumiem dlaczego tu jest przecinek) performing a variety of roles.
Their presence in the activated sludge can cause 'such' (w zlym miejscu, nie dawaj tego slowa tutaj) disruption to plant operation, SUCH as filamentous bulking or its foaming.
Unfortunately, none of the currently used approaches 'do not' (to jest niepotr - bo masz juz 'none of') give a complete guarantee OF eliminatING them.
To identify filamentous organisms 'are used in various types of identification keys' (to jest zle - trzeba...various types of identification keys are used).
More recent solution (do czego? musisz napisac) is the molecular 'methods' (nie moze tak byc, bo masz czasownik l. poj 'is' a rzeczownik l. mnogiej - albo jedno albo drugie) based on (brak przedimka THE) analysis of DNA and RNA of the bacteria. 'They' (nie jest jasno do czego to sie odnosi - napisz 'these tests') are considered more reliable and less subject to error.
For sludge application 'now found a method' (to jest zle, tutaj ...a new method has been found) that uses unique (ale co? tu brakuje rzeczownika) for each type of microbial 16S rRNA. Based on (brak przedimka A) 16S rRNA sequence of the known (ale czego? tu brakuje rzeczownika do slowa 'known' - albo ujmij to inaczej) , it is possible to design probes that react with 'the' (nie jestem pewna czy 'the' , moze 'this') specific sequence. 'They' (ale co? nie jestem pewna o czym mowa) can be used for (brak THE) dyeing of certain bacteria. In this way it is possible to identify the bacteria 'by FISH' (tego nie rozumiem, czy 'fish' sie zmieniaja w jakis sposob - jak tak, to musisz napisac..changes in the cos tam of fish). Furthermore, many types of bacteria HAVE still not been identified taxonomically. In recent times 'we' (prosze, nie mieszaj mnie w to..lepiej 'scientists (albo ktos tam) have') discovered and described approx. 40 new morphotypes of filamentous bacteria.