Hostes sciebant Romanos frumento egere et hanc rem Caesari summum periculum adlaturam esse.
I think I can handle it after I have checked up in the vocabulary.Here is my translation to supplement yours:
"The enemy knew that Romans were lacking of grain and that this matter would bring Caesar great danger."
The subjects of the clause of indirect statement,ie,"Romans" and "this matter" take on accusative forms thus producing "Romanos" and "hanc rem",and the verbs in the clause are infinitives:"egere",---present infinitive, and "adlaturus,-a,-um esse"---future active infinitive of "adferre",which means "bring,cause,give",etc.
NB the future infinitive should agree with their subjects in case,gender,and number,just as if it were an adjective. So "adlaturam" goes with "hanc rem"
Hope you have already got the idea
Fortunas tibi bonas